pre-coalesce.mir
3.54 KB
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# RUN: llc -mtriple=x86_64-unknown-linux-gnu -run-pass simple-register-coalescing -o - %s | FileCheck %s
# Check there is no partial redundent copy left in the loop after register coalescing.
--- |
; ModuleID = '<stdin>'
source_filename = "<stdin>"
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
@b = common local_unnamed_addr global i8* null, align 8
@a = common local_unnamed_addr global i32 0, align 4
define i32 @foo() local_unnamed_addr {
entry:
%t0 = load i8*, i8** @b, align 8
%t1 = load i8, i8* %t0, align 1
%cmp4 = icmp eq i8 %t1, 0
%t2 = load i32, i32* @a, align 4
br i1 %cmp4, label %while.end, label %while.body.preheader
while.body.preheader: ; preds = %entry
br label %while.body
while.body: ; preds = %while.body, %while.body.preheader
%t3 = phi i32 [ %add3, %while.body ], [ %t2, %while.body.preheader ]
%t4 = phi i8 [ %t5, %while.body ], [ %t1, %while.body.preheader ]
%conv = sext i8 %t4 to i32
%add = mul i32 %t3, 33
%add3 = add nsw i32 %add, %conv
store i32 %add3, i32* @a, align 4
%t5 = load i8, i8* %t0, align 1
%cmp = icmp eq i8 %t5, 0
br i1 %cmp, label %while.end, label %while.body
while.end: ; preds = %while.body, %entry
%.lcssa = phi i32 [ %t2, %entry ], [ %add3, %while.body ]
ret i32 %.lcssa
}
...
---
# Check A = B and B = A copies will not exist in the loop at the same time.
# CHECK: name: foo
# CHECK: [[L1:bb.3]].{{[a-zA-Z0-9.]+}}:
# CHECK: %[[REGA:.*]] = COPY %[[REGB:.*]]
# CHECK-NOT: %[[REGB]] = COPY %[[REGA]]
# CHECK: JCC_1 %[[L1]], 5
name: foo
alignment: 16
exposesReturnsTwice: false
legalized: false
regBankSelected: false
selected: false
tracksRegLiveness: true
registers:
- { id: 0, class: gr64 }
- { id: 1, class: gr8 }
- { id: 2, class: gr32 }
- { id: 3, class: gr32 }
- { id: 4, class: gr8 }
- { id: 5, class: gr32 }
- { id: 6, class: gr8 }
- { id: 7, class: gr32 }
- { id: 8, class: gr32 }
- { id: 9, class: gr32 }
- { id: 10, class: gr32 }
- { id: 11, class: gr32 }
- { id: 12, class: gr8 }
- { id: 13, class: gr32 }
frameInfo:
isFrameAddressTaken: false
isReturnAddressTaken: false
hasStackMap: false
hasPatchPoint: false
stackSize: 0
offsetAdjustment: 0
maxAlignment: 0
adjustsStack: false
hasCalls: false
maxCallFrameSize: 0
hasOpaqueSPAdjustment: false
hasVAStart: false
hasMustTailInVarArgFunc: false
body: |
bb.0.entry:
%0 = MOV64rm $rip, 1, $noreg, @b, $noreg :: (dereferenceable load 8 from @b)
%12 = MOV8rm %0, 1, $noreg, 0, $noreg :: (load 1 from %ir.t0)
TEST8rr %12, %12, implicit-def $eflags
%11 = MOV32rm $rip, 1, $noreg, @a, $noreg :: (dereferenceable load 4 from @a)
JCC_1 %bb.1, 5, implicit killed $eflags
bb.4:
%10 = COPY %11
JMP_1 %bb.3
bb.1.while.body.preheader:
bb.2.while.body:
%8 = MOVSX32rr8 %12
%10 = COPY %11
%10 = SHL32ri %10, 5, implicit-def dead $eflags
%10 = ADD32rr %10, %11, implicit-def dead $eflags
%10 = ADD32rr %10, %8, implicit-def dead $eflags
MOV32mr $rip, 1, $noreg, @a, $noreg, %10 :: (store 4 into @a)
%12 = MOV8rm %0, 1, $noreg, 0, $noreg :: (load 1 from %ir.t0)
TEST8rr %12, %12, implicit-def $eflags
%11 = COPY %10
JCC_1 %bb.2, 5, implicit killed $eflags
JMP_1 %bb.3
bb.3.while.end:
$eax = COPY %10
RET 0, killed $eax
...