Imported Upstream version 6.10.0.49

Former-commit-id: 1d6753294b2993e1fbf92de9366bb9544db4189b

external/llvm-project/llvm/test/Transforms/JumpThreading/2008-11-27-EntryMunge.ll

@@ -0,0 +1,13 @@
+; RUN: opt < %s -jump-threading -S | grep "ret i32 0"
+; PR3138
+
+define i32 @jt() {
+entry:
+       br i1 true, label %bb3, label %bb
+
+bb:             ; preds = %entry
+       unreachable
+
+bb3:            ; preds = %entry
+       ret i32 0
+}

external/llvm-project/llvm/test/Transforms/JumpThreading/2010-08-26-and.ll

@@ -0,0 +1,162 @@
+; RUN: opt -jump-threading -S < %s | FileCheck %s
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
+target triple = "x86_64-apple-darwin10.0.0"
+
+%class.StringSwitch = type { i8*, i32, i32, i8 }
+
+@.str = private constant [4 x i8] c"red\00"       ; <[4 x i8]*> [#uses=1]
+@.str1 = private constant [7 x i8] c"orange\00"   ; <[7 x i8]*> [#uses=1]
+@.str2 = private constant [7 x i8] c"yellow\00"   ; <[7 x i8]*> [#uses=1]
+@.str3 = private constant [6 x i8] c"green\00"    ; <[6 x i8]*> [#uses=1]
+@.str4 = private constant [5 x i8] c"blue\00"     ; <[5 x i8]*> [#uses=1]
+@.str5 = private constant [7 x i8] c"indigo\00"   ; <[7 x i8]*> [#uses=1]
+@.str6 = private constant [7 x i8] c"violet\00"   ; <[7 x i8]*> [#uses=1]
+@.str7 = private constant [12 x i8] c"Color = %d\0A\00" ; <[12 x i8]*> [#uses=1]
+
+define i32 @main(i32 %argc, i8** nocapture %argv) nounwind ssp {
+entry:
+  %cmp142 = icmp sgt i32 %argc, 1                 ; <i1> [#uses=1]
+  br i1 %cmp142, label %bb.nph, label %for.end
+
+bb.nph:                                           ; preds = %entry
+  %tmp = add i32 %argc, -2                        ; <i32> [#uses=1]
+  %tmp144 = zext i32 %tmp to i64                  ; <i64> [#uses=1]
+  %tmp145 = add i64 %tmp144, 1                    ; <i64> [#uses=1]
+  br label %land.lhs.true.i
+
+land.lhs.true.i:                                  ; preds = %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit134, %bb.nph
+  %retval.0.i.pre161 = phi i32 [ undef, %bb.nph ], [ %retval.0.i.pre, %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit134 ] ; <i32> [#uses=3]
+  %indvar = phi i64 [ 0, %bb.nph ], [ %tmp146, %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit134 ] ; <i64> [#uses=1]
+  %tmp146 = add i64 %indvar, 1                    ; <i64> [#uses=3]
+  %arrayidx = getelementptr i8*, i8** %argv, i64 %tmp146 ; <i8**> [#uses=1]
+  %tmp6 = load i8*, i8** %arrayidx, align 8            ; <i8*> [#uses=8]
+  %call.i.i = call i64 @strlen(i8* %tmp6) nounwind ; <i64> [#uses=1]
+  %conv.i.i = trunc i64 %call.i.i to i32          ; <i32> [#uses=6]\
+; CHECK: switch i32 %conv.i.i
+; CHECK-NOT: if.then.i40
+; CHECK: }
+  switch i32 %conv.i.i, label %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit [
+    i32 3, label %land.lhs.true5.i
+    i32 6, label %land.lhs.true5.i37
+  ]
+
+land.lhs.true5.i:                                 ; preds = %land.lhs.true.i
+  %call.i = call i32 @memcmp(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i64 0, i64 0), i8* %tmp6, i64 4) nounwind ; <i32> [#uses=1]
+  %cmp9.i = icmp eq i32 %call.i, 0                ; <i1> [#uses=1]
+  br i1 %cmp9.i, label %_ZN12StringSwitchI5ColorE4CaseILj4EEERS1_RAT__KcRKS0_.exit, label %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit
+
+_ZN12StringSwitchI5ColorE4CaseILj4EEERS1_RAT__KcRKS0_.exit: ; preds = %land.lhs.true5.i
+  br label %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit
+
+land.lhs.true5.i37:                               ; preds = %land.lhs.true.i
+  %call.i35 = call i32 @memcmp(i8* getelementptr inbounds ([7 x i8], [7 x i8]* @.str1, i64 0, i64 0), i8* %tmp6, i64 7) nounwind ; <i32> [#uses=1]
+  %cmp9.i36 = icmp eq i32 %call.i35, 0            ; <i1> [#uses=1]
+  br i1 %cmp9.i36, label %if.then.i40, label %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit
+
+if.then.i40:                                      ; preds = %land.lhs.true5.i37
+  br label %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit
+
+_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit: ; preds = %if.then.i40, %land.lhs.true5.i37, %_ZN12StringSwitchI5ColorE4CaseILj4EEERS1_RAT__KcRKS0_.exit, %land.lhs.true5.i, %land.lhs.true.i
+  %retval.0.i.pre159 = phi i32 [ 1, %_ZN12StringSwitchI5ColorE4CaseILj4EEERS1_RAT__KcRKS0_.exit ], [ %retval.0.i.pre161, %land.lhs.true5.i37 ], [ 2, %if.then.i40 ], [ %retval.0.i.pre161, %land.lhs.true5.i ], [ %retval.0.i.pre161, %land.lhs.true.i ] ; <i32> [#uses=2]
+  %tmp2.i44 = phi i8 [ 1, %_ZN12StringSwitchI5ColorE4CaseILj4EEERS1_RAT__KcRKS0_.exit ], [ 0, %land.lhs.true5.i37 ], [ 1, %if.then.i40 ], [ 0, %land.lhs.true5.i ], [ 0, %land.lhs.true.i ] ; <i8> [#uses=3]
+  %tobool.i46 = icmp eq i8 %tmp2.i44, 0           ; <i1> [#uses=1]
+  %cmp.i49 = icmp eq i32 %conv.i.i, 6             ; <i1> [#uses=1]
+  %or.cond = and i1 %tobool.i46, %cmp.i49         ; <i1> [#uses=1]
+  br i1 %or.cond, label %land.lhs.true5.i55, label %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit60
+
+land.lhs.true5.i55:                               ; preds = %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit
+  %call.i53 = call i32 @memcmp(i8* getelementptr inbounds ([7 x i8], [7 x i8]* @.str2, i64 0, i64 0), i8* %tmp6, i64 7) nounwind ; <i32> [#uses=1]
+  %cmp9.i54 = icmp eq i32 %call.i53, 0            ; <i1> [#uses=1]
+  br i1 %cmp9.i54, label %if.then.i58, label %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit60
+
+if.then.i58:                                      ; preds = %land.lhs.true5.i55
+  br label %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit60
+
+_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit60: ; preds = %if.then.i58, %land.lhs.true5.i55, %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit
+  %retval.0.i.pre158 = phi i32 [ %retval.0.i.pre159, %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit ], [ %retval.0.i.pre159, %land.lhs.true5.i55 ], [ 3, %if.then.i58 ] ; <i32> [#uses=2]
+  %tmp2.i63 = phi i8 [ %tmp2.i44, %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit ], [ %tmp2.i44, %land.lhs.true5.i55 ], [ 1, %if.then.i58 ] ; <i8> [#uses=3]
+  %tmp14.i64 = and i8 %tmp2.i63, 1                ; <i8> [#uses=1]
+  %tobool.i65 = icmp eq i8 %tmp14.i64, 0          ; <i1> [#uses=1]
+  %cmp.i68 = icmp eq i32 %conv.i.i, 5             ; <i1> [#uses=1]
+  %or.cond168 = and i1 %tobool.i65, %cmp.i68      ; <i1> [#uses=1]
+  br i1 %or.cond168, label %land.lhs.true5.i74, label %_ZN12StringSwitchI5ColorE4CaseILj6EEERS1_RAT__KcRKS0_.exit
+
+land.lhs.true5.i74:                               ; preds = %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit60
+  %call.i72 = call i32 @memcmp(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str3, i64 0, i64 0), i8* %tmp6, i64 6) nounwind ; <i32> [#uses=1]
+  %cmp9.i73 = icmp eq i32 %call.i72, 0            ; <i1> [#uses=1]
+  br i1 %cmp9.i73, label %if.then.i77, label %_ZN12StringSwitchI5ColorE4CaseILj6EEERS1_RAT__KcRKS0_.exit
+
+if.then.i77:                                      ; preds = %land.lhs.true5.i74
+  br label %_ZN12StringSwitchI5ColorE4CaseILj6EEERS1_RAT__KcRKS0_.exit
+
+_ZN12StringSwitchI5ColorE4CaseILj6EEERS1_RAT__KcRKS0_.exit: ; preds = %if.then.i77, %land.lhs.true5.i74, %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit60
+  %retval.0.i.pre157 = phi i32 [ %retval.0.i.pre158, %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit60 ], [ %retval.0.i.pre158, %land.lhs.true5.i74 ], [ 4, %if.then.i77 ] ; <i32> [#uses=2]
+  %tmp2.i81 = phi i8 [ %tmp2.i63, %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit60 ], [ %tmp2.i63, %land.lhs.true5.i74 ], [ 1, %if.then.i77 ] ; <i8> [#uses=3]
+  %tmp14.i82 = and i8 %tmp2.i81, 1                ; <i8> [#uses=1]
+  %tobool.i83 = icmp eq i8 %tmp14.i82, 0          ; <i1> [#uses=1]
+  %cmp.i86 = icmp eq i32 %conv.i.i, 4             ; <i1> [#uses=1]
+  %or.cond169 = and i1 %tobool.i83, %cmp.i86      ; <i1> [#uses=1]
+  br i1 %or.cond169, label %land.lhs.true5.i92, label %_ZN12StringSwitchI5ColorE4CaseILj5EEERS1_RAT__KcRKS0_.exit
+
+land.lhs.true5.i92:                               ; preds = %_ZN12StringSwitchI5ColorE4CaseILj6EEERS1_RAT__KcRKS0_.exit
+  %call.i90 = call i32 @memcmp(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str4, i64 0, i64 0), i8* %tmp6, i64 5) nounwind ; <i32> [#uses=1]
+  %cmp9.i91 = icmp eq i32 %call.i90, 0            ; <i1> [#uses=1]
+  br i1 %cmp9.i91, label %if.then.i95, label %_ZN12StringSwitchI5ColorE4CaseILj5EEERS1_RAT__KcRKS0_.exit
+
+if.then.i95:                                      ; preds = %land.lhs.true5.i92
+  br label %_ZN12StringSwitchI5ColorE4CaseILj5EEERS1_RAT__KcRKS0_.exit
+
+_ZN12StringSwitchI5ColorE4CaseILj5EEERS1_RAT__KcRKS0_.exit: ; preds = %if.then.i95, %land.lhs.true5.i92, %_ZN12StringSwitchI5ColorE4CaseILj6EEERS1_RAT__KcRKS0_.exit
+  %retval.0.i.pre156 = phi i32 [ %retval.0.i.pre157, %_ZN12StringSwitchI5ColorE4CaseILj6EEERS1_RAT__KcRKS0_.exit ], [ %retval.0.i.pre157, %land.lhs.true5.i92 ], [ 5, %if.then.i95 ] ; <i32> [#uses=2]
+  %tmp2.i99 = phi i8 [ %tmp2.i81, %_ZN12StringSwitchI5ColorE4CaseILj6EEERS1_RAT__KcRKS0_.exit ], [ %tmp2.i81, %land.lhs.true5.i92 ], [ 1, %if.then.i95 ] ; <i8> [#uses=3]
+  %tmp14.i100 = and i8 %tmp2.i99, 1               ; <i8> [#uses=1]
+  %tobool.i101 = icmp eq i8 %tmp14.i100, 0        ; <i1> [#uses=1]
+  %cmp.i104 = icmp eq i32 %conv.i.i, 6            ; <i1> [#uses=1]
+  %or.cond170 = and i1 %tobool.i101, %cmp.i104    ; <i1> [#uses=1]
+  br i1 %or.cond170, label %land.lhs.true5.i110, label %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit115
+
+land.lhs.true5.i110:                              ; preds = %_ZN12StringSwitchI5ColorE4CaseILj5EEERS1_RAT__KcRKS0_.exit
+  %call.i108 = call i32 @memcmp(i8* getelementptr inbounds ([7 x i8], [7 x i8]* @.str5, i64 0, i64 0), i8* %tmp6, i64 7) nounwind ; <i32> [#uses=1]
+  %cmp9.i109 = icmp eq i32 %call.i108, 0          ; <i1> [#uses=1]
+  br i1 %cmp9.i109, label %if.then.i113, label %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit115
+
+if.then.i113:                                     ; preds = %land.lhs.true5.i110
+  br label %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit115
+
+_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit115: ; preds = %if.then.i113, %land.lhs.true5.i110, %_ZN12StringSwitchI5ColorE4CaseILj5EEERS1_RAT__KcRKS0_.exit
+  %retval.0.i.pre155 = phi i32 [ %retval.0.i.pre156, %_ZN12StringSwitchI5ColorE4CaseILj5EEERS1_RAT__KcRKS0_.exit ], [ %retval.0.i.pre156, %land.lhs.true5.i110 ], [ 6, %if.then.i113 ] ; <i32> [#uses=2]
+  %tmp2.i118 = phi i8 [ %tmp2.i99, %_ZN12StringSwitchI5ColorE4CaseILj5EEERS1_RAT__KcRKS0_.exit ], [ %tmp2.i99, %land.lhs.true5.i110 ], [ 1, %if.then.i113 ] ; <i8> [#uses=3]
+  %tmp14.i119 = and i8 %tmp2.i118, 1              ; <i8> [#uses=1]
+  %tobool.i120 = icmp eq i8 %tmp14.i119, 0        ; <i1> [#uses=1]
+  %cmp.i123 = icmp eq i32 %conv.i.i, 6            ; <i1> [#uses=1]
+  %or.cond171 = and i1 %tobool.i120, %cmp.i123    ; <i1> [#uses=1]
+  br i1 %or.cond171, label %land.lhs.true5.i129, label %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit134
+
+land.lhs.true5.i129:                              ; preds = %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit115
+  %call.i127 = call i32 @memcmp(i8* getelementptr inbounds ([7 x i8], [7 x i8]* @.str6, i64 0, i64 0), i8* %tmp6, i64 7) nounwind ; <i32> [#uses=1]
+  %cmp9.i128 = icmp eq i32 %call.i127, 0          ; <i1> [#uses=1]
+  br i1 %cmp9.i128, label %if.then.i132, label %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit134
+
+if.then.i132:                                     ; preds = %land.lhs.true5.i129
+  br label %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit134
+
+_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit134: ; preds = %if.then.i132, %land.lhs.true5.i129, %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit115
+  %retval.0.i.pre = phi i32 [ %retval.0.i.pre155, %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit115 ], [ %retval.0.i.pre155, %land.lhs.true5.i129 ], [ 7, %if.then.i132 ] ; <i32> [#uses=2]
+  %tmp2.i137 = phi i8 [ %tmp2.i118, %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit115 ], [ %tmp2.i118, %land.lhs.true5.i129 ], [ 1, %if.then.i132 ] ; <i8> [#uses=1]
+  %tmp7.i138 = and i8 %tmp2.i137, 1               ; <i8> [#uses=1]
+  %tobool.i139 = icmp eq i8 %tmp7.i138, 0         ; <i1> [#uses=1]
+  %retval.0.i = select i1 %tobool.i139, i32 0, i32 %retval.0.i.pre ; <i32> [#uses=1]
+  %call22 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str7, i64 0, i64 0), i32 %retval.0.i) ; <i32> [#uses=0]
+  %exitcond = icmp eq i64 %tmp146, %tmp145        ; <i1> [#uses=1]
+  br i1 %exitcond, label %for.end, label %land.lhs.true.i
+
+for.end:                                          ; preds = %_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit134, %entry
+  ret i32 0
+}
+
+declare i32 @printf(i8* nocapture, ...) nounwind
+
+declare i32 @memcmp(i8* nocapture, i8* nocapture, i64) nounwind readonly
+
+declare i64 @strlen(i8* nocapture) nounwind readonly

external/llvm-project/llvm/test/Transforms/JumpThreading/2011-04-02-SimplifyDeadBlock.ll

@@ -0,0 +1,32 @@
+; RUN: opt < %s -jump-threading
+; PR9446
+; Just check that it doesn't crash
+
+define void @int327() nounwind {
+entry:
+  unreachable
+
+for.cond:                                         ; preds = %for.cond4
+  %tobool3 = icmp eq i8 undef, 0
+  br i1 %tobool3, label %for.cond23, label %for.cond4
+
+for.cond4:                                        ; preds = %for.cond
+  br label %for.cond
+
+for.cond23:                                       ; preds = %for.body28, %for.cond23, %for.cond
+  %conv321 = phi i32 [ %conv32, %for.body28 ], [ 0, %for.cond ], [ %conv321, %for.cond23 ]
+  %l_266.0 = phi i32 [ %phitmp, %for.body28 ], [ 0, %for.cond ], [ 0, %for.cond23 ]
+  %cmp26 = icmp eq i32 %l_266.0, 0
+  br i1 %cmp26, label %for.body28, label %for.cond23
+
+for.body28:                                       ; preds = %for.cond23
+  %and = and i32 %conv321, 1
+  %conv32 = zext i8 undef to i32
+  %add = add nsw i32 %l_266.0, 1
+  %phitmp = and i32 %add, 255
+  br label %for.cond23
+
+if.end43:                                         ; No predecessors!
+  ret void
+}
+

external/llvm-project/llvm/test/Transforms/JumpThreading/2011-04-14-InfLoop.ll

@@ -0,0 +1,27 @@
+; RUN: opt -jump-threading < %s
+; <rdar://problem/9284786>
+
+%0 = type <{ i64, i16, i64, i8, i8 }>
+
+@g_338 = external global %0, align 8
+
+define void @func_1() nounwind ssp {
+entry:
+  ret void
+
+for.cond1177:
+  %inc1187 = add nsw i32 0, 1
+  %cmp1179 = icmp slt i32 %inc1187, 5
+  br i1 %cmp1179, label %for.cond1177, label %land.rhs1320
+
+land.rhs1320:
+  %tmp1324 = load volatile i64, i64* getelementptr inbounds (%0, %0* @g_338, i64 0, i32 2), align 1
+  br label %if.end.i
+
+if.end.i:
+  %tobool.pr.i = phi i1 [ false, %if.end.i ], [ false, %land.rhs1320 ]
+  br i1 %tobool.pr.i, label %return, label %if.end.i
+
+return:
+  ret void
+}

external/llvm-project/llvm/test/Transforms/JumpThreading/2012-07-19-NoSuccessorIndirectBr.ll

@@ -0,0 +1,8 @@
+; RUN: opt < %s -jump-threading
+; PR 13405
+; Just check that it doesn't crash / assert
+
+define i32 @f() nounwind {
+entry:
+  indirectbr i8* undef, []
+}

external/llvm-project/llvm/test/Transforms/JumpThreading/and-and-cond.ll

@@ -0,0 +1,37 @@
+; RUN: opt < %s -jump-threading -mem2reg -instcombine -simplifycfg  -S | FileCheck %s
+
+declare i32 @f1()
+declare i32 @f2()
+declare void @f3()
+
+define i32 @test(i1 %cond, i1 %cond2, i1 %cond3) {
+; CHECK: test
+	br i1 %cond, label %T1, label %F1
+
+; CHECK-NOT: T1:
+T1:
+	%v1 = call i32 @f1()
+	br label %Merge
+
+F1:
+	%v2 = call i32 @f2()
+	br label %Merge
+
+Merge:
+; CHECK: Merge:
+; CHECK: %v1 = call i32 @f1()
+; CHECK-NEXT: %D = and i1 %cond2, %cond3
+; CHECK-NEXT: br i1 %D
+	%A = phi i1 [true, %T1], [false, %F1]
+	%B = phi i32 [%v1, %T1], [%v2, %F1]
+	%C = and i1 %A, %cond2
+	%D = and i1 %C, %cond3
+	br i1 %D, label %T2, label %F2
+
+T2:
+	call void @f3()
+	ret i32 %B
+
+F2:
+	ret i32 %B
+}

external/llvm-project/llvm/test/Transforms/JumpThreading/and-cond.ll

@@ -0,0 +1,35 @@
+; RUN: opt < %s -jump-threading -mem2reg -instcombine -simplifycfg  -S | FileCheck %s
+
+declare i32 @f1()
+declare i32 @f2()
+declare void @f3()
+
+define i32 @test(i1 %cond, i1 %cond2) {
+; CHECK: test
+	br i1 %cond, label %T1, label %F1
+
+; CHECK-NOT: T1
+T1:
+	%v1 = call i32 @f1()
+	br label %Merge
+
+F1:
+	%v2 = call i32 @f2()
+	br label %Merge
+
+Merge:
+; CHECK: Merge:
+; CHECK: %v1 = call i32 @f1()
+; CHECK-NEXT: br i1 %cond2
+	%A = phi i1 [true, %T1], [false, %F1]
+	%B = phi i32 [%v1, %T1], [%v2, %F1]
+	%C = and i1 %A, %cond2
+	br i1 %C, label %T2, label %F2
+
+T2:
+	call void @f3()
+	ret i32 %B
+
+F2:
+	ret i32 %B
+}

external/llvm-project/llvm/test/Transforms/JumpThreading/assume-edge-dom.ll

@@ -0,0 +1,39 @@
+; RUN: opt -S -jump-threading < %s | FileCheck %s
+
+declare i8* @escape()
+declare void @llvm.assume(i1)
+
+define i1 @test1(i1 %cond) {
+entry:
+    br i1 %cond, label %taken, label %not_taken
+
+; CHECK-LABEL: @test1
+; CHECK: br i1 %cond, label %no, label %yes
+; CHECK: ret i1 true
+
+taken:
+    %res1 = call i8* @escape()
+    %a = icmp eq i8* %res1, null
+    tail call void @llvm.assume(i1 %a)
+    br label %done
+not_taken:
+    %res2 = call i8* @escape()
+    %b = icmp ne i8* %res2, null
+    tail call void @llvm.assume(i1 %b)
+    br label %done
+
+; An assume that can be used to simplify this comparison dominates each
+; predecessor branch (although no assume dominates the cmp itself). Make sure
+; this still can be simplified.
+
+done:
+    %res = phi i8* [ %res1, %taken ], [ %res2, %not_taken ]
+    %cnd = icmp ne i8* %res, null
+    br i1 %cnd, label %yes, label %no
+
+yes:
+    ret i1 true
+no:
+    ret i1 false
+}
+

external/llvm-project/llvm/test/Transforms/JumpThreading/assume.ll

@@ -0,0 +1,241 @@
+; RUN: opt -S -jump-threading -dce < %s | FileCheck %s
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; Function Attrs: nounwind uwtable
+define i32 @test1(i32 %a, i32 %b) #0 {
+entry:
+  %cmp = icmp sgt i32 %a, 5
+  tail call void @llvm.assume(i1 %cmp)
+  %cmp1 = icmp sgt i32 %b, 1234
+  br i1 %cmp1, label %if.then, label %if.else
+
+; CHECK-LABEL: @test1
+; CHECK: icmp sgt i32 %a, 5
+; CHECK: call void @llvm.assume
+; CHECK-NOT: icmp sgt i32 %a, 3
+; CHECK: ret i32
+
+if.then:                                          ; preds = %entry
+  %cmp2 = icmp sgt i32 %a, 3
+  br i1 %cmp2, label %if.then3, label %return
+
+if.then3:                                         ; preds = %if.then
+  tail call void (...) @bar() #1
+  br label %return
+
+if.else:                                          ; preds = %entry
+  tail call void (...) @car() #1
+  br label %return
+
+return:                                           ; preds = %if.else, %if.then, %if.then3
+  %retval.0 = phi i32 [ 1, %if.then3 ], [ 0, %if.then ], [ 0, %if.else ]
+  ret i32 %retval.0
+}
+
+define i32 @test2(i32 %a) #0 {
+entry:
+  %cmp = icmp sgt i32 %a, 5
+  tail call void @llvm.assume(i1 %cmp)
+  %cmp1 = icmp sgt i32 %a, 3
+  br i1 %cmp1, label %if.then, label %return
+
+; CHECK-LABEL: @test2
+; CHECK: icmp sgt i32 %a, 5
+; CHECK: tail call void @llvm.assume
+; CHECK: tail call void (...) @bar()
+; CHECK: ret i32 1
+
+
+if.then:                                          ; preds = %entry
+  tail call void (...) @bar() #1
+  br label %return
+
+return:                                           ; preds = %entry, %if.then
+  %retval.0 = phi i32 [ 1, %if.then ], [ 0, %entry ]
+  ret i32 %retval.0
+}
+
+@g = external global i32
+
+; Check that we do prove a fact using an assume within the block.
+; We can fold the assume based on the semantics of assume.
+define void @can_fold_assume(i32* %array) {
+; CHECK-LABEL: @can_fold_assume
+; CHECK-NOT: call void @llvm.assume
+; CHECK-NOT: br
+; CHECK: ret void
+  %notnull = icmp ne i32* %array, null
+  call void @llvm.assume(i1 %notnull)
+  br i1 %notnull, label %normal, label %error
+
+normal:
+  ret void
+
+error:
+  store atomic i32 0, i32* @g unordered, align 4
+  ret void
+}
+
+declare void @f(i1)
+declare void @exit()
+; We can fold the assume but not the uses before the assume.
+define void @cannot_fold_use_before_assume(i32* %array) {
+; CHECK-LABEL:@cannot_fold_use_before_assume
+; CHECK: @f(i1 %notnull)
+; CHECK-NEXT: exit()
+; CHECK-NOT: assume
+; CHECK-NEXT: ret void
+  %notnull = icmp ne i32* %array, null
+  call void @f(i1 %notnull)
+  call void @exit()
+  call void @llvm.assume(i1 %notnull)
+  br i1 %notnull, label %normal, label %error
+
+normal:
+  ret void
+
+error:
+  store atomic i32 0, i32* @g unordered, align 4
+  ret void
+}
+
+declare void @dummy(i1) nounwind argmemonly
+define void @can_fold_some_use_before_assume(i32* %array) {
+
+; CHECK-LABEL:@can_fold_some_use_before_assume
+; CHECK: @f(i1 %notnull)
+; CHECK-NEXT: @dummy(i1 true)
+; CHECK-NOT: assume
+; CHECK-NEXT: ret void
+  %notnull = icmp ne i32* %array, null
+  call void @f(i1 %notnull)
+  call void @dummy(i1 %notnull)
+  call void @llvm.assume(i1 %notnull)
+  br i1 %notnull, label %normal, label %error
+
+normal:
+  ret void
+
+error:
+  store atomic i32 0, i32* @g unordered, align 4
+  ret void
+
+}
+
+; FIXME: can fold assume and all uses before/after assume.
+; because the trapping exit call is after the assume.
+define void @can_fold_assume_and_all_uses(i32* %array) {
+; CHECK-LABEL:@can_fold_assume_and_all_uses
+; CHECK: @dummy(i1 %notnull)
+; CHECK-NEXT: assume(i1 %notnull)
+; CHECK-NEXT: exit()
+; CHECK-NEXT: %notnull2 = or i1 true, false
+; CHECK-NEXT: @f(i1 %notnull2)
+; CHECK-NEXT: ret void
+  %notnull = icmp ne i32* %array, null
+  call void @dummy(i1 %notnull)
+  call void @llvm.assume(i1 %notnull)
+  call void @exit()
+  br i1 %notnull, label %normal, label %error
+
+normal:
+  %notnull2 = or i1 %notnull, false
+  call void @f(i1 %notnull2)
+  ret void
+
+error:
+  store atomic i32 0, i32* @g unordered, align 4
+  ret void
+}
+
+declare void @fz(i8)
+; FIXME: We can fold assume to true, and the use after assume, but we do not do so
+; currently, because of the function call after the assume.
+define void @can_fold_assume2(i32* %array) {
+
+; CHECK-LABEL:@can_fold_assume2
+; CHECK: @f(i1 %notnull)
+; CHECK-NEXT: assume(i1 %notnull)
+; CHECK-NEXT: znotnull = zext i1 %notnull to i8
+; CHECK-NEXT: @f(i1 %notnull)
+; CHECK-NEXT: @f(i1 true)
+; CHECK-NEXT: @fz(i8 %znotnull)
+; CHECK-NEXT: ret void
+  %notnull = icmp ne i32* %array, null
+  call void @f(i1 %notnull)
+  call void @llvm.assume(i1 %notnull)
+  %znotnull = zext i1 %notnull to i8
+  call void @f(i1 %notnull)
+  br i1 %notnull, label %normal, label %error
+
+normal:
+  call void @f(i1 %notnull)
+  call void @fz(i8 %znotnull)
+  ret void
+
+error:
+  store atomic i32 0, i32* @g unordered, align 4
+  ret void
+}
+
+declare void @llvm.experimental.guard(i1, ...)
+; FIXME: We can fold assume to true, but we do not do so
+; because of the guard following the assume.
+define void @can_fold_assume3(i32* %array){
+
+; CHECK-LABEL:@can_fold_assume3
+; CHECK: @f(i1 %notnull)
+; CHECK-NEXT: assume(i1 %notnull)
+; CHECK-NEXT: guard(i1 %notnull)
+; CHECK-NEXT: znotnull = zext i1 true to i8
+; CHECK-NEXT: @f(i1 true)
+; CHECK-NEXT: @fz(i8 %znotnull)
+; CHECK-NEXT: ret void
+  %notnull = icmp ne i32* %array, null
+  call void @f(i1 %notnull)
+  call void @llvm.assume(i1 %notnull)
+  call void(i1, ...) @llvm.experimental.guard(i1 %notnull) [ "deopt"() ]
+  %znotnull = zext i1 %notnull to i8
+  br i1 %notnull, label %normal, label %error
+
+normal:
+  call void @f(i1 %notnull)
+  call void @fz(i8 %znotnull)
+  ret void
+
+error:
+  store atomic i32 0, i32* @g unordered, align 4
+  ret void
+}
+
+
+; can fold all uses and remove the cond
+define void @can_fold_assume4(i32* %array) {
+; CHECK-LABEL: can_fold_assume4
+; CHECK-NOT: notnull
+; CHECK: dummy(i1 true)
+; CHECK-NEXT: ret void
+  %notnull = icmp ne i32* %array, null
+  call void @exit()
+  call void @dummy(i1 %notnull)
+  call void @llvm.assume(i1 %notnull)
+  br i1 %notnull, label %normal, label %error
+
+normal:
+  ret void
+
+error:
+  store atomic i32 0, i32* @g unordered, align 4
+  ret void
+}
+; Function Attrs: nounwind
+declare void @llvm.assume(i1) #1
+
+declare void @bar(...)
+
+declare void @car(...)
+
+attributes #0 = { nounwind uwtable }
+attributes #1 = { nounwind }
+

external/llvm-project/llvm/test/Transforms/JumpThreading/branch-no-const.ll

@@ -0,0 +1,21 @@
+; RUN: opt < %s -jump-threading -S | not grep phi
+
+declare i8 @mcguffin()
+
+define i32 @test(i1 %foo, i8 %b) {
+entry:
+  %a = call i8 @mcguffin()
+  br i1 %foo, label %bb1, label %bb2
+bb1:
+  br label %jt
+bb2:
+  br label %jt
+jt:
+  %x = phi i8 [%a, %bb1], [%b, %bb2]
+  %A = icmp eq i8 %x, %a
+  br i1 %A, label %rt, label %rf
+rt:
+  ret i32 7
+rf:
+  ret i32 8
+}

external/llvm-project/llvm/test/Transforms/JumpThreading/compare.ll

@@ -0,0 +1,30 @@
+; There should be no phi nodes left.
+; RUN: opt < %s -jump-threading  -S | not grep "phi i32"
+
+declare i32 @f1()
+declare i32 @f2()
+declare void @f3()
+
+define i32 @test(i1 %cond) {
+	br i1 %cond, label %T1, label %F1
+
+T1:
+	%v1 = call i32 @f1()
+	br label %Merge
+
+F1:
+	%v2 = call i32 @f2()
+	br label %Merge
+
+Merge:
+	%B = phi i32 [%v1, %T1], [12, %F1]
+	%A = icmp ne i32 %B, 42
+	br i1 %A, label %T2, label %F2
+
+T2:
+	call void @f3()
+	ret i32 1
+
+F2:
+	ret i32 0
+}

external/llvm-project/llvm/test/Transforms/JumpThreading/conservative-lvi.ll

@@ -0,0 +1,58 @@
+; RUN: opt -jump-threading -S %s | FileCheck %s
+
+; Check that we thread arg2neg -> checkpos -> end.
+;
+; LazyValueInfo would previously fail to analyze the value of %arg in arg2neg
+; because its predecessing blocks (checkneg) hadn't been processed yet (PR21238)
+
+; CHECK-LABEL: @test_jump_threading
+; CHECK: arg2neg:
+; CHECK-NEXT: br i1 %arg1, label %end, label %checkpos.thread
+; CHECK: checkpos.thread:
+; CHECK-NEXT: br label %end
+
+define i32 @test_jump_threading(i1 %arg1, i32 %arg2) {
+checkneg:
+  %cmp = icmp slt i32 %arg2, 0
+  br i1 %cmp, label %arg2neg, label %checkpos
+
+arg2neg:
+  br i1 %arg1, label %end, label %checkpos
+
+checkpos:
+  %cmp2 = icmp sgt i32 %arg2, 0
+  br i1 %cmp2, label %arg2pos, label %end
+
+arg2pos:
+  br label %end
+
+end:
+  %0 = phi i32 [ 1, %arg2neg ], [ 2, %checkpos ], [ 3, %arg2pos ]
+  ret i32 %0
+}
+
+
+; arg2neg has an edge back to itself. If LazyValueInfo is not careful when
+; visiting predecessors, it could get into an infinite loop.
+
+; CHECK-LABEL: test_infinite_loop
+
+define i32 @test_infinite_loop(i1 %arg1, i32 %arg2) {
+checkneg:
+  %cmp = icmp slt i32 %arg2, 0
+  br i1 %cmp, label %arg2neg, label %checkpos
+
+arg2neg:
+  br i1 %arg1, label %arg2neg, label %checkpos
+
+checkpos:
+  %cmp2 = icmp sgt i32 %arg2, 0
+  br i1 %cmp2, label %arg2pos, label %end
+
+arg2pos:
+  br label %end
+
+end:
+  %0 = phi i32 [ 2, %checkpos ], [ 3, %arg2pos ]
+  ret i32 %0
+}

external/llvm-project/llvm/test/Transforms/JumpThreading/ddt-crash3.ll

@@ -0,0 +1,43 @@
+; RUN: opt < %s -jump-threading -disable-output -verify-dom-info
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@global = external local_unnamed_addr global i64, align 8
+@global.1 = external local_unnamed_addr global i64, align 8
+@global.2 = external local_unnamed_addr global i64, align 8
+
+; Function Attrs: norecurse noreturn nounwind uwtable
+define void @hoge() local_unnamed_addr #0 {
+bb:
+  br label %bb1
+
+bb1:                                              ; preds = %bb26, %bb
+  %tmp = load i64, i64* @global, align 8, !tbaa !1
+  %tmp2 = icmp eq i64 %tmp, 0
+  br i1 %tmp2, label %bb27, label %bb3
+
+bb3:                                              ; preds = %bb1
+  %tmp4 = load i64, i64* @global.1, align 8, !tbaa !1
+  %tmp5 = icmp eq i64 %tmp4, 0
+  br i1 %tmp5, label %bb23, label %bb23
+
+bb23:                                             ; preds = %bb3, %bb3
+  br label %bb26
+
+bb26:                                             ; preds = %bb27, %bb23
+  br label %bb1
+
+bb27:                                             ; preds = %bb1
+  br label %bb26
+}
+
+attributes #0 = { norecurse noreturn nounwind uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.ident = !{!0}
+
+!0 = !{!"clang version 7.0.0 "}
+!1 = !{!2, !2, i64 0}
+!2 = !{!"long", !3, i64 0}
+!3 = !{!"omnipotent char", !4, i64 0}
+!4 = !{!"Simple C/C++ TBAA"}

external/llvm-project/llvm/test/Transforms/JumpThreading/ddt-crash4.ll

@@ -0,0 +1,75 @@
+; RUN: opt < %s -jump-threading -disable-output -verify-dom-info
+@global = external global i64, align 8
+
+define void @f() {
+bb:
+  br label %bb1
+
+bb1:
+  %tmp = load i64, i64* @global, align 8
+  %tmp2 = icmp eq i64 %tmp, 0
+  br i1 %tmp2, label %bb27, label %bb3
+
+bb3:
+  %tmp4 = load i64, i64* @global, align 8
+  %tmp5 = icmp eq i64 %tmp4, 0
+  br i1 %tmp5, label %bb6, label %bb7
+
+bb6:
+  br label %bb7
+
+bb7:
+  %tmp8 = phi i1 [ true, %bb3 ], [ undef, %bb6 ]
+  %tmp9 = select i1 %tmp8, i64 %tmp4, i64 0
+  br i1 false, label %bb10, label %bb23
+
+bb10:
+  %tmp11 = load i64, i64* @global, align 8
+  %tmp12 = icmp slt i64 %tmp11, 5
+  br i1 %tmp12, label %bb13, label %bb17
+
+bb13:
+  br label %bb14
+
+bb14:
+  br i1 undef, label %bb15, label %bb16
+
+bb15:
+  unreachable
+
+bb16:
+  br label %bb10
+
+bb17:
+  br label %bb18
+
+bb18:
+  br i1 undef, label %bb22, label %bb13
+
+bb19:
+  br i1 undef, label %bb20, label %bb21
+
+bb20:
+  unreachable
+
+bb21:
+  br label %bb18
+
+bb22:
+  br label %bb23
+
+bb23:
+  br i1 undef, label %bb24, label %bb13
+
+bb24:
+  br i1 undef, label %bb26, label %bb25
+
+bb25:
+  br label %bb19
+
+bb26:
+  br label %bb1
+
+bb27:
+  br label %bb24
+}

external/llvm-project/llvm/test/Transforms/JumpThreading/degenerate-phi.ll

@@ -0,0 +1,24 @@
+; RUN: opt -jump-threading -disable-output < %s
+; PR9112
+
+; This is actually a test for value tracking. Jump threading produces
+; "%phi = phi i16" when it removes all edges leading to %unreachable.
+; The .ll parser won't let us write that directly since it's invalid code.
+
+define void @func() nounwind {
+entry:
+  br label %bb
+
+bb:
+  br label %bb
+
+unreachable:
+  %phi = phi i16 [ %add, %unreachable ], [ 0, %next ]
+  %add = add i16 0, %phi
+  %cmp = icmp slt i16 %phi, 0
+  br i1 %cmp, label %unreachable, label %next
+
+next:
+  br label %unreachable
+}
+

external/llvm-project/llvm/test/Transforms/JumpThreading/fold-not-thread.ll

@@ -0,0 +1,246 @@
+; RUN: opt -jump-threading -S -verify < %s | FileCheck %s
+
+declare i32 @f1()
+declare i32 @f2()
+declare void @f3()
+declare void @f4(i32)
+
+
+; Make sure we update the phi node properly.
+;
+; CHECK-LABEL: define void @test_br_folding_not_threading_update_phi(
+; CHECK: br label %L1
+; Make sure we update the phi node properly here, i.e. we only have 2 predecessors, entry and L0
+; CHECK: %res.0 = phi i32 [ 0, %L0 ], [ 1, %entry ]
+define void @test_br_folding_not_threading_update_phi(i32 %val) nounwind {
+entry:
+  %cmp = icmp eq i32 %val, 32
+  br i1 %cmp, label %L0, label %L1
+L0:
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  switch i32 %val, label %L2 [
+    i32 0, label %L1
+    i32 32, label %L1
+  ]
+
+L1:
+	%res.0 = phi i32 [ 0, %L0 ], [ 0, %L0 ], [1, %entry]
+  call void @f4(i32 %res.0)
+  ret void
+L2:
+  call void @f3()
+  ret void
+}
+
+; Make sure we can fold this branch ... We will not be able to thread it as
+; L0 is too big to duplicate. L2 is the unreachable block here.
+;
+; CHECK-LABEL: @test_br_folding_not_threading(
+; CHECK: L1:
+; CHECK: call i32 @f2()
+; CHECK: call void @f3()
+; CHECK-NEXT: ret void
+; CHECK-NOT: br
+; CHECK: L3:
+define void @test_br_folding_not_threading(i1 %cond) nounwind {
+entry:
+  br i1 %cond, label %L0, label %L3 
+L0:
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  br i1 %cond, label %L1, label %L2 
+
+L1:
+  call void @f3()
+  ret void
+L2:
+  call void @f3()
+  ret void
+L3:
+  call void @f3()
+  ret void
+}
+
+
+; Make sure we can fold this branch ... We will not be able to thread it as
+; L0 is too big to duplicate. L2 is the unreachable block here.
+; With more than 1 predecessors.
+;
+; CHECK-LABEL: @test_br_folding_not_threading_multiple_preds(
+; CHECK: L1:
+; CHECK: call i32 @f2()
+; CHECK: call void @f3()
+; CHECK-NEXT: ret void
+; CHECK-NOT: br
+; CHECK: L3:
+define void @test_br_folding_not_threading_multiple_preds(i1 %condx, i1 %cond) nounwind {
+entry:
+  br i1 %condx, label %X0, label %X1
+
+X0:
+  br i1 %cond, label %L0, label %L3 
+
+X1:
+  br i1 %cond, label %L0, label %L3 
+
+L0:
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  br i1 %cond, label %L1, label %L2 
+
+L1:
+  call void @f3()
+  ret void
+L2:
+  call void @f3()
+  ret void
+L3:
+  call void @f3()
+  ret void
+}
+
+; Make sure we can do the RAUW for %add...
+;
+; CHECK-LABEL: @rauw_if_possible(
+; CHECK: call void @f4(i32 96)
+define void @rauw_if_possible(i32 %value) nounwind {
+entry:
+  %cmp = icmp eq i32 %value, 32
+  br i1 %cmp, label %L0, label %L3 
+L0:
+  call i32 @f2()
+  call i32 @f2()
+  %add = add i32 %value, 64
+  switch i32 %add, label %L3 [
+    i32 32, label %L1
+    i32 96, label %L2
+    ]
+
+L1:
+  call void @f3()
+  ret void
+L2:
+  call void @f4(i32 %add)
+  ret void
+L3:
+  call void @f3()
+  ret void
+}
+
+; Make sure we can NOT do the RAUW for %add...
+;
+; CHECK-LABEL: @rauw_if_possible2(
+; CHECK: call void @f4(i32 %add) 
+define void @rauw_if_possible2(i32 %value) nounwind {
+entry:
+  %cmp = icmp eq i32 %value, 32
+  %add = add i32 %value, 64
+  br i1 %cmp, label %L0, label %L2 
+L0:
+  call i32 @f2()
+  call i32 @f2()
+  switch i32 %add, label %L3 [
+    i32 32, label %L1
+    i32 96, label %L2
+    ]
+
+L1:
+  call void @f3()
+  ret void
+L2:
+  call void @f4(i32 %add)
+  ret void
+L3:
+  call void @f3()
+  ret void
+}
+
+; Make sure we can fold this branch ... We will not be able to thread it as
+; L0 is too big to duplicate.
+; We do not attempt to rewrite the indirectbr target here, but we still take
+; its target after L0 into account and that enables us to fold.
+;
+; L2 is the unreachable block here.
+; 
+; CHECK-LABEL: @test_br_folding_not_threading_indirect_branch(
+; CHECK: L1:
+; CHECK: call i32 @f2()
+; CHECK: call void @f3()
+; CHECK-NEXT: ret void
+; CHECK-NOT: br
+; CHECK: L3:
+define void @test_br_folding_not_threading_indirect_branch(i1 %condx, i1 %cond) nounwind {
+entry:
+  br i1 %condx, label %X0, label %X1
+
+X0:
+  br i1 %cond, label %L0, label %L3
+
+X1:
+  br i1 %cond, label %XX1, label %L3
+
+XX1:
+  indirectbr i8* blockaddress(@test_br_folding_not_threading_indirect_branch, %L0), [label %L0]
+
+L0:
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  call i32 @f2()
+  br i1 %cond, label %L1, label %L2
+
+L1:
+  call void @f3()
+  ret void
+
+L2:
+  call void @f3()
+  ret void
+
+L3:
+  call void @f3()
+  ret void
+}

external/llvm-project/llvm/test/Transforms/JumpThreading/guards.ll

@@ -0,0 +1,383 @@
+; RUN: opt < %s -jump-threading -dce -S | FileCheck %s
+
+declare void @llvm.experimental.guard(i1, ...)
+
+declare i32 @f1()
+declare i32 @f2()
+
+define i32 @branch_implies_guard(i32 %a) {
+; CHECK-LABEL: @branch_implies_guard(
+  %cond = icmp slt i32 %a, 10
+  br i1 %cond, label %T1, label %F1
+
+T1:
+; CHECK:       T1.split
+; CHECK:         %v1 = call i32 @f1()
+; CHECK-NEXT:    %retVal
+; CHECK-NEXT:    br label %Merge
+  %v1 = call i32 @f1()
+  br label %Merge
+
+F1:
+; CHECK:       F1.split
+; CHECK:         %v2 = call i32 @f2()
+; CHECK-NEXT:    %retVal
+; CHECK-NEXT:    %condGuard
+; CHECK-NEXT:    call void (i1, ...) @llvm.experimental.guard(i1 %condGuard
+; CHECK-NEXT:    br label %Merge
+  %v2 = call i32 @f2()
+  br label %Merge
+
+Merge:
+; CHECK:       Merge
+; CHECK-NOT:     call void(i1, ...) @llvm.experimental.guard(
+  %retPhi = phi i32 [ %v1, %T1 ], [ %v2, %F1 ]
+  %retVal = add i32 %retPhi, 10
+  %condGuard = icmp slt i32 %a, 20
+  call void(i1, ...) @llvm.experimental.guard(i1 %condGuard) [ "deopt"() ]
+  ret i32 %retVal
+}
+
+define i32 @not_branch_implies_guard(i32 %a) {
+; CHECK-LABEL: @not_branch_implies_guard(
+  %cond = icmp slt i32 %a, 20
+  br i1 %cond, label %T1, label %F1
+
+T1:
+; CHECK:       T1.split:
+; CHECK-NEXT:    %v1 = call i32 @f1()
+; CHECK-NEXT:    %retVal
+; CHECK-NEXT:    %condGuard
+; CHECK-NEXT:    call void (i1, ...) @llvm.experimental.guard(i1 %condGuard
+; CHECK-NEXT:    br label %Merge
+  %v1 = call i32 @f1()
+  br label %Merge
+
+F1:
+; CHECK:       F1.split:
+; CHECK-NEXT:   %v2 = call i32 @f2()
+; CHECK-NEXT:   %retVal
+; CHECK-NEXT:   br label %Merge
+  %v2 = call i32 @f2()
+  br label %Merge
+
+Merge:
+; CHECK:       Merge
+; CHECK-NOT:     call void(i1, ...) @llvm.experimental.guard(
+  %retPhi = phi i32 [ %v1, %T1 ], [ %v2, %F1 ]
+  %retVal = add i32 %retPhi, 10
+  %condGuard = icmp sgt i32 %a, 10
+  call void(i1, ...) @llvm.experimental.guard(i1 %condGuard) [ "deopt"() ]
+  ret i32 %retVal
+}
+
+define i32 @branch_overlaps_guard(i32 %a) {
+; CHECK-LABEL: @branch_overlaps_guard(
+  %cond = icmp slt i32 %a, 20
+  br i1 %cond, label %T1, label %F1
+
+T1:
+; CHECK:        T1:
+; CHECK-NEXT:      %v1 = call i32 @f1()
+; CHECK-NEXT:      br label %Merge
+  %v1 = call i32 @f1()
+  br label %Merge
+
+F1:
+; CHECK:        F1:
+; CHECK-NEXT:     %v2 = call i32 @f2()
+; CHECK-NEXT:     br label %Merge
+  %v2 = call i32 @f2()
+  br label %Merge
+
+Merge:
+; CHECK:       Merge
+; CHECK:         %condGuard = icmp slt i32 %a, 10
+; CHECK-NEXT:    call void (i1, ...) @llvm.experimental.guard(i1 %condGuard) [ "deopt"() ]
+  %retPhi = phi i32 [ %v1, %T1 ], [ %v2, %F1 ]
+  %retVal = add i32 %retPhi, 10
+  %condGuard = icmp slt i32 %a, 10
+  call void(i1, ...) @llvm.experimental.guard(i1 %condGuard) [ "deopt"() ]
+  ret i32 %retVal
+}
+
+define i32 @branch_doesnt_overlap_guard(i32 %a) {
+; CHECK-LABEL: @branch_doesnt_overlap_guard(
+  %cond = icmp slt i32 %a, 10
+  br i1 %cond, label %T1, label %F1
+
+T1:
+; CHECK:        T1:
+; CHECK-NEXT:      %v1 = call i32 @f1()
+; CHECK-NEXT:      br label %Merge
+  %v1 = call i32 @f1()
+  br label %Merge
+
+F1:
+; CHECK:        F1:
+; CHECK-NEXT:     %v2 = call i32 @f2()
+; CHECK-NEXT:     br label %Merge
+  %v2 = call i32 @f2()
+  br label %Merge
+
+Merge:
+; CHECK:       Merge
+; CHECK:         %condGuard = icmp sgt i32 %a, 20
+; CHECK-NEXT:    call void (i1, ...) @llvm.experimental.guard(i1 %condGuard) [ "deopt"() ]
+  %retPhi = phi i32 [ %v1, %T1 ], [ %v2, %F1 ]
+  %retVal = add i32 %retPhi, 10
+  %condGuard = icmp sgt i32 %a, 20
+  call void(i1, ...) @llvm.experimental.guard(i1 %condGuard) [ "deopt"() ]
+  ret i32 %retVal
+}
+
+define i32 @not_a_diamond1(i32 %a, i1 %cond1) {
+; CHECK-LABEL: @not_a_diamond1(
+  br i1 %cond1, label %Pred, label %Exit
+
+Pred:
+; CHECK:       Pred:
+; CHECK-NEXT:    switch i32 %a, label %Exit
+  switch i32 %a, label %Exit [
+    i32 10, label %Merge
+    i32 20, label %Merge
+  ]
+
+Merge:
+; CHECK:       Merge:
+; CHECK-NEXT:    call void (i1, ...) @llvm.experimental.guard(i1 %cond1) [ "deopt"() ]
+; CHECK-NEXT:    br label %Exit
+  call void(i1, ...) @llvm.experimental.guard(i1 %cond1) [ "deopt"() ]
+  br label %Exit
+
+Exit:
+; CHECK:       Exit:
+; CHECK-NEXT:    ret i32 %a
+  ret i32 %a
+}
+
+define void @not_a_diamond2(i32 %a, i1 %cond1) {
+; CHECK-LABEL: @not_a_diamond2(
+  br label %Parent
+
+Merge:
+  call void(i1, ...) @llvm.experimental.guard(i1 %cond1)[ "deopt"() ]
+  ret void
+
+Pred:
+; CHECK-NEXT:  Pred:
+; CHECK-NEXT:    switch i32 %a, label %Exit
+  switch i32 %a, label %Exit [
+    i32 10, label %Merge
+    i32 20, label %Merge
+  ]
+
+Parent:
+  br label %Pred
+
+Exit:
+; CHECK:       Merge:
+; CHECK-NEXT:    call void (i1, ...) @llvm.experimental.guard(i1 %cond1) [ "deopt"() ]
+; CHECK-NEXT:    ret void
+  ret void
+}
+
+declare void @never_called(i1)
+
+; LVI uses guard to identify value of %c2 in branch as true, we cannot replace that
+; guard with guard(true & c1).
+define void @dont_fold_guard(i8* %addr, i32 %i, i32 %length) {
+; CHECK-LABEL: dont_fold_guard
+; CHECK: %wide.chk = and i1 %c1, %c2
+; CHECK-NEXT: experimental.guard(i1 %wide.chk)
+; CHECK-NEXT: call void @never_called(i1 true)
+; CHECK-NEXT: ret void
+  %c1 = icmp ult i32 %i, %length
+  %c2 = icmp eq i32 %i, 0
+  %wide.chk = and i1 %c1, %c2
+  call void(i1, ...) @llvm.experimental.guard(i1 %wide.chk) [ "deopt"() ]
+  br i1 %c2, label %BB1, label %BB2
+
+BB1:
+  call void @never_called(i1 %c2)
+  ret void
+
+BB2:
+  ret void
+}
+
+declare void @dummy(i1) nounwind argmemonly
+; same as dont_fold_guard1 but there's a use immediately after guard and before
+; branch. We can fold that use.
+define void @dont_fold_guard2(i8* %addr, i32 %i, i32 %length) {
+; CHECK-LABEL: dont_fold_guard2
+; CHECK: %wide.chk = and i1 %c1, %c2
+; CHECK-NEXT: experimental.guard(i1 %wide.chk)
+; CHECK-NEXT: dummy(i1 true)
+; CHECK-NEXT: call void @never_called(i1 true)
+; CHECK-NEXT: ret void
+  %c1 = icmp ult i32 %i, %length
+  %c2 = icmp eq i32 %i, 0
+  %wide.chk = and i1 %c1, %c2
+  call void(i1, ...) @llvm.experimental.guard(i1 %wide.chk) [ "deopt"() ]
+  call void @dummy(i1 %c2)
+  br i1 %c2, label %BB1, label %BB2
+
+BB1:
+  call void @never_called(i1 %c2)
+  ret void
+
+BB2:
+  ret void
+}
+
+; same as dont_fold_guard1 but condition %cmp is not an instruction.
+; We cannot fold the guard under any circumstance.
+; FIXME: We can merge unreachableBB2 into not_zero.
+define void @dont_fold_guard3(i8* %addr, i1 %cmp, i32 %i, i32 %length) {
+; CHECK-LABEL: dont_fold_guard3
+; CHECK: guard(i1 %cmp)
+  call void(i1, ...) @llvm.experimental.guard(i1 %cmp) [ "deopt"() ]
+  br i1 %cmp, label %BB1, label %BB2
+
+BB1:
+  call void @never_called(i1 %cmp)
+  ret void
+
+BB2:
+  ret void
+}
+
+declare void @f(i1)
+; Same as dont_fold_guard1 but use switch instead of branch.
+; triggers source code `ProcessThreadableEdges`.
+define void @dont_fold_guard4(i1 %cmp1, i32 %i) nounwind {
+; CHECK-LABEL: dont_fold_guard4 
+; CHECK-LABEL: L2:
+; CHECK-NEXT: %cmp = icmp eq i32 %i, 0 
+; CHECK-NEXT: guard(i1 %cmp)
+; CHECK-NEXT: dummy(i1 true)
+; CHECK-NEXT: @f(i1 true)
+; CHECK-NEXT: ret void
+entry:
+  br i1 %cmp1, label %L0, label %L3 
+L0:
+  %cmp = icmp eq i32 %i, 0
+  call void(i1, ...) @llvm.experimental.guard(i1 %cmp) [ "deopt"() ]
+  call void @dummy(i1 %cmp)
+  switch i1 %cmp, label %L3 [
+    i1 false, label %L1
+    i1 true, label %L2
+    ]
+
+L1:
+  ret void
+L2:
+  call void @f(i1 %cmp)
+  ret void
+L3:
+  ret void
+}
+
+; Make sure that we don't PRE a non-speculable load across a guard.
+define void @unsafe_pre_across_guard(i8* %p, i1 %load.is.valid) {
+
+; CHECK-LABEL: @unsafe_pre_across_guard(
+; CHECK-NOT:   loaded.pr
+; CHECK:       entry:
+; CHECK-NEXT:    br label %loop
+; CHECK:       loop:
+; CHECK-NEXT:    call void (i1, ...) @llvm.experimental.guard(i1 %load.is.valid) [ "deopt"() ]
+; CHECK-NEXT:    %loaded = load i8, i8* %p
+; CHECK-NEXT:    %continue = icmp eq i8 %loaded, 0
+; CHECK-NEXT:    br i1 %continue, label %exit, label %loop
+entry:
+  br label %loop
+
+loop:                                             ; preds = %loop, %entry
+  call void (i1, ...) @llvm.experimental.guard(i1 %load.is.valid) [ "deopt"() ]
+  %loaded = load i8, i8* %p
+  %continue = icmp eq i8 %loaded, 0
+  br i1 %continue, label %exit, label %loop
+
+exit:                                             ; preds = %loop
+  ret void
+}
+
+; Make sure that we can safely PRE a speculable load across a guard.
+define void @safe_pre_across_guard(i8* noalias nocapture readonly dereferenceable(8) %p, i1 %load.is.valid) {
+
+; CHECK-LABEL: @safe_pre_across_guard(
+; CHECK:       entry:
+; CHECK-NEXT:    %loaded.pr = load i8, i8* %p
+; CHECK-NEXT:    br label %loop
+; CHECK:       loop:
+; CHECK-NEXT:    %loaded = phi i8 [ %loaded, %loop ], [ %loaded.pr, %entry ]
+; CHECK-NEXT:    call void (i1, ...) @llvm.experimental.guard(i1 %load.is.valid) [ "deopt"() ]
+; CHECK-NEXT:    %continue = icmp eq i8 %loaded, 0
+; CHECK-NEXT:    br i1 %continue, label %exit, label %loop
+
+entry:
+  br label %loop
+
+loop:                                             ; preds = %loop, %entry
+  call void (i1, ...) @llvm.experimental.guard(i1 %load.is.valid) [ "deopt"() ]
+  %loaded = load i8, i8* %p
+  %continue = icmp eq i8 %loaded, 0
+  br i1 %continue, label %exit, label %loop
+
+exit:                                             ; preds = %loop
+  ret void
+}
+
+; Make sure that we don't PRE a non-speculable load across a call which may
+; alias with the load.
+define void @unsafe_pre_across_call(i8* %p) {
+
+; CHECK-LABEL: @unsafe_pre_across_call(
+; CHECK-NOT:   loaded.pr
+; CHECK:       entry:
+; CHECK-NEXT:    br label %loop
+; CHECK:       loop:
+; CHECK-NEXT:    call i32 @f1()
+; CHECK-NEXT:    %loaded = load i8, i8* %p
+; CHECK-NEXT:    %continue = icmp eq i8 %loaded, 0
+; CHECK-NEXT:    br i1 %continue, label %exit, label %loop
+entry:
+  br label %loop
+
+loop:                                             ; preds = %loop, %entry
+  call i32 @f1()
+  %loaded = load i8, i8* %p
+  %continue = icmp eq i8 %loaded, 0
+  br i1 %continue, label %exit, label %loop
+
+exit:                                             ; preds = %loop
+  ret void
+}
+
+; Make sure that we can safely PRE a speculable load across a call.
+define void @safe_pre_across_call(i8* noalias nocapture readonly dereferenceable(8) %p) {
+
+; CHECK-LABEL: @safe_pre_across_call(
+; CHECK:       entry:
+; CHECK-NEXT:    %loaded.pr = load i8, i8* %p
+; CHECK-NEXT:    br label %loop
+; CHECK:       loop:
+; CHECK-NEXT:    %loaded = phi i8 [ %loaded, %loop ], [ %loaded.pr, %entry ]
+; CHECK-NEXT:    call i32 @f1()
+; CHECK-NEXT:    %continue = icmp eq i8 %loaded, 0
+; CHECK-NEXT:    br i1 %continue, label %exit, label %loop
+
+entry:
+  br label %loop
+
+loop:                                             ; preds = %loop, %entry
+  call i32 @f1()
+  %loaded = load i8, i8* %p
+  %continue = icmp eq i8 %loaded, 0
+  br i1 %continue, label %exit, label %loop
+
+exit:                                             ; preds = %loop
+  ret void
+}

external/llvm-project/llvm/test/Transforms/JumpThreading/header-succ.ll

@@ -0,0 +1,99 @@
+; RUN: opt -S -jump-threading < %s | FileCheck %s
+
+; Check that the heuristic for avoiding accidental introduction of irreducible
+; loops doesn't also prevent us from threading simple constructs where this
+; isn't a problem.
+
+declare void @opaque_body()
+
+define void @jump_threading_loopheader() {
+; CHECK-LABEL: @jump_threading_loopheader
+top:
+    br label %entry
+
+entry:
+    %ind = phi i32 [0, %top], [%nextind, %latch]
+    %nextind = add i32 %ind, 1
+    %cmp = icmp ule i32 %ind, 10
+; CHECK: br i1 %cmp, label %latch, label %exit
+    br i1 %cmp, label %body, label %latch
+
+body:
+    call void @opaque_body()
+; CHECK: br label %entry
+    br label %latch
+
+latch:
+    %cond = phi i2 [1, %entry], [2, %body]
+    switch i2 %cond, label %unreach [
+        i2 2, label %entry
+        i2 1, label %exit
+    ]
+
+unreach:
+    unreachable
+
+exit:
+    ret void
+}
+
+; We also need to check the opposite order of the branches, in the switch
+; instruction because jump-threading relies on that to decide which edge to
+; try to thread first.
+define void @jump_threading_loopheader2() {
+; CHECK-LABEL: @jump_threading_loopheader2
+top:
+    br label %entry
+
+entry:
+    %ind = phi i32 [0, %top], [%nextind, %latch]
+    %nextind = add i32 %ind, 1
+    %cmp = icmp ule i32 %ind, 10
+; CHECK: br i1 %cmp, label %exit, label %latch
+    br i1 %cmp, label %body, label %latch
+
+body:
+    call void @opaque_body()
+; CHECK: br label %entry
+    br label %latch
+
+latch:
+    %cond = phi i2 [1, %entry], [2, %body]
+    switch i2 %cond, label %unreach [
+        i2 1, label %entry
+        i2 2, label %exit
+    ]
+
+unreach:
+    unreachable
+
+exit:
+    ret void
+}
+
+; Check if we can handle undef branch condition.
+define void @jump_threading_loopheader3() {
+; CHECK-LABEL: @jump_threading_loopheader3
+top:
+    br label %entry
+
+entry:
+    %ind = phi i32 [0, %top], [%nextind, %latch]
+    %nextind = add i32 %ind, 1
+    %cmp = icmp ule i32 %ind, 10
+; CHECK: br i1 %cmp, label %latch, label %exit
+    br i1 %cmp, label %body, label %latch
+
+body:
+    call void @opaque_body()
+; CHECK: br label %entry
+    br label %latch
+
+latch:
+   %phi = phi i32 [undef, %entry], [0, %body]
+   %cmp1 = icmp eq i32 %phi, 0
+   br i1 %cmp1, label %entry, label %exit
+
+exit:
+    ret void
+}