select-intrinsic-x86-flags-read-u32.mir 817 Bytes
# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
# RUN: llc -mtriple=i386-- -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s

# 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.

--- |
  define void @read_flags() { ret void }
  ; CHECK-LABEL: name: read_flags
  ; CHECK: bb.0:
  ; CHECK:   [[RDFLAGS32_:%[0-9]+]]:gr32 = RDFLAGS32 implicit-def $esp, implicit $esp
  ; CHECK:   $eax = COPY [[RDFLAGS32_]]
...

---
name:            read_flags
legalized:       true
regBankSelected: true

registers:
  - { id: 0, class: gpr }

body:             |
  bb.0:
    %0(s32) = G_INTRINSIC_W_SIDE_EFFECTS intrinsic(@llvm.x86.flags.read.u32)
    $eax = COPY %0(s32)
...