Imported Upstream version 5.18.0.246

Former-commit-id: 0c7ce5b1a7851e13f22acfd379b7f9fb304e4833

external/llvm/test/CodeGen/Mips/Fast-ISel/stackloadstore.ll

@@ -0,0 +1,18 @@
+; RUN: llc < %s -march=mipsel -mcpu=mips32 -fast-isel -disable-fp-elim -relocation-model=pic < %s
+
+; Test that negative array access don't crash constant synthesis when fast isel
+; generates negative offsets.
+
+define i16 @test() {
+  %a = alloca [4 x i16], align 4
+  %arrayidx = getelementptr inbounds [4 x i16], [4 x i16]* %a, i32 0, i32 -2
+  %b = load i16, i16* %arrayidx, align 2
+  ret i16 %b
+}
+
+define void @test2() {
+  %a = alloca [4 x i16], align 4
+  %arrayidx = getelementptr inbounds [4 x i16], [4 x i16]* %a, i32 0, i32 -2
+  store i16 2, i16* %arrayidx, align 2
+  ret void
+}