# RUN: llc -mtriple=aarch64-apple-ios -run-pass=register-coalescer -verify-machineinstrs %s -o - | FileCheck %s
--- |
declare void @f2()
define void @func0() { ret void }
define void @func1() { ret void }
define void @func2() { ret void }
...
---
# Check coalescing of COPYs from reserved physregs.
# CHECK-LABEL: name: func0
name: func0
body: |
bb.0:
; We usually should not coalesce copies from allocatable physregs.
; CHECK: %0:gpr32 = COPY $w7
; CHECK: STRWui %0, $x1, 0
%0 : gpr32 = COPY $w7
STRWui %0, $x1, 0
; It is fine to coalesce copies from reserved physregs
; CHECK-NOT: COPY
; CHECK: STRXui $fp, $x1, 0
%1 : gpr64 = COPY $fp
STRXui %1, $x1, 0
; It is not fine to coalesce copies from reserved physregs when they are
; clobbered.
; CHECK: %2:gpr64 = COPY $fp
; CHECK: STRXui %2, $x1, 0
%2 : gpr64 = COPY $fp
$fp = SUBXri $fp, 4, 0
STRXui %2, $x1, 0
; Is is fine to coalesce copies from constant physregs even when they are
; clobbered.
; CHECK-NOT: COPY
; CHECK: STRWui $wzr, $x1
%3 : gpr32 = COPY $wzr
dead $wzr = SUBSWri $w1, 0, 0, implicit-def $nzcv
STRWui %3, $x1, 0
; Is is fine to coalesce copies from constant physregs even when they are
; clobbered.
; CHECK-NOT: COPY
; CHECK: STRXui $xzr, $x1
%4 : gpr64 = COPY $xzr
dead $wzr = SUBSWri $w1, 0, 0, implicit-def $nzcv
STRXui %4, $x1, 0
; Coalescing COPYs into constant physregs.
; CHECK: $wzr = SUBSWri $w1, 0, 0
%5 : gpr32 = SUBSWri $w1, 0, 0, implicit-def $nzcv
$wzr = COPY %5
; Only coalesce when the source register is reserved as a whole (this is
; a limitation of the current code which cannot update liveness information
; of the non-reserved part).
; CHECK: %6:xseqpairsclass = COPY $x28_fp
; CHECK: HINT 0, implicit %6
%6 : xseqpairsclass = COPY $x28_fp
HINT 0, implicit %6
; It is not fine to coalesce copies from reserved physregs when they are
; clobbered by the regmask on a call.
; CHECK: %7:gpr64 = COPY $x18
; CHECK: BL @f2, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit-def $sp
; CHECK: STRXui %7, $x1, 0
; Need a def of x18 so that it's not deduced as "constant".
$x18 = COPY $xzr
%7 : gpr64 = COPY $x18
BL @f2, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit-def $sp
STRXui %7, $x1, 0
; This can be coalesced.
; CHECK: $fp = SUBXri $fp, 4, 0
%8 : gpr64sp = SUBXri $fp, 4, 0
$fp = COPY %8
; Cannot coalesce when there are reads of the physreg.
; CHECK-NOT: $fp = SUBXri $fp, 8, 0
; CHECK: %9:gpr64sp = SUBXri $fp, 8, 0
; CHECK: STRXui $fp, $fp, 0
; CHECK: $fp = COPY %9
%9 : gpr64sp = SUBXri $fp, 8, 0
STRXui $fp, $fp, 0
$fp = COPY %9
...
---
# Check coalescing of COPYs from reserved physregs.
# CHECK-LABEL: name: func1
name: func1
body: |
bb.0:
; Cannot coalesce physreg because we have reads on other CFG paths (we
; currently abort for any control flow)
; CHECK-NOT: $fp = SUBXri
; CHECK: %0:gpr64sp = SUBXri $fp, 12, 0
; CHECK: CBZX undef $x0, %bb.1
; CHECK: B %bb.2
%0 : gpr64sp = SUBXri $fp, 12, 0
CBZX undef $x0, %bb.1
B %bb.2
bb.1:
$fp = COPY %0
RET_ReallyLR
bb.2:
STRXui $fp, $fp, 0
RET_ReallyLR
...
---
# CHECK-LABEL: name: func2
name: func2
body: |
bb.0:
; We can coalesce copies from physreg to vreg across multiple blocks.
; CHECK-NOT: COPY
; CHECK: CBZX undef $x0, %bb.1
; CHECK-NEXT: B %bb.2
%0 : gpr64sp = COPY $fp
CBZX undef $x0, %bb.1
B %bb.2
bb.1:
; CHECK: STRXui undef $x0, $fp, 0
; CHECK-NEXT: RET_ReallyLR
STRXui undef $x0, %0, 0
RET_ReallyLR
bb.2:
RET_ReallyLR
...
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