Imported Upstream version 6.10.0.49

Former-commit-id: 1d6753294b2993e1fbf92de9366bb9544db4189b

external/llvm-project/llvm/test/CodeGen/X86/GlobalISel/select-intrinsic-x86-flags-read-u32.mir

@@ -0,0 +1,27 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -mtriple=i386-- -run-pass=instruction-select -verify-machineinstrs -global-isel %s -o - | FileCheck %s
+
+--- |
+  define void @read_flags() { ret void }
+...
+
+---
+# Check that we select a the x86.flags.read.u32 intrinsic into a RDFLAGS
+# instruction. Also check that we constrain the register class of the COPY to
+# gr32.
+name:            read_flags
+legalized:       true
+regBankSelected: true
+
+registers:
+  - { id: 0, class: gpr }
+
+body:             |
+  bb.0:
+    ; CHECK-LABEL: name: read_flags
+    ; CHECK: [[RDFLAGS32_:%[0-9]+]]:gr32 = RDFLAGS32 implicit-def %esp, implicit %esp
+    ; CHECK: [[SUBREG_TO_REG:%[0-9]+]]:gr64 = SUBREG_TO_REG 0, [[RDFLAGS32_]], %subreg.sub_32bit
+    ; CHECK: %rax = COPY [[SUBREG_TO_REG]]
+    %0(s32) = G_INTRINSIC_W_SIDE_EFFECTS intrinsic(@llvm.x86.flags.read.u32)
+    %rax = COPY %0(s32)
+...