simple-register-allocation-read-undef.mir
730 Bytes
# RUN: llc < %s -x=mir -mtriple=x86_64-- -run-pass=simple-register-coalescing | FileCheck %s
---
name: f
body: |
bb.0:
JCC_1 %bb.2, 2, undef implicit killed $eflags
JMP_1 %bb.1
bb.1:
%0 : gr64 = IMPLICIT_DEF
NOOP implicit-def undef %1.sub_32bit : gr64
NOOP implicit-def %1.sub_16bit : gr64
JMP_1 %bb.3
bb.2:
NOOP implicit-def %0
%1 = COPY %0
bb.3:
NOOP implicit killed %0
NOOP implicit killed %1
...
# We should have a setting of both sub_32bit and sub_16bit. The first one
# should be undef and not dead, and the second should not be undef.
# CHECK-NOT: dead
# CHECK: NOOP implicit-def undef %1.sub_32bit
# CHECK-NOT: undef
# CHECK-NEXT: NOOP implicit-def %1.sub_16bit