forked from OSchip/llvm-project
140 lines
3.9 KiB
YAML
140 lines
3.9 KiB
YAML
# RUN: llc -run-pass=branch-folder %s -o - | FileCheck %s
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# PR33980
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# Don't form conditional tail calls when the original conditional branch has
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# the same true and false destination. Otherwise, when we remove the tail call
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# successor we will also remove the fallthrough successor from the CFG.
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# CHECK: body: |
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# CHECK: bb.0.entry:
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# CHECK: successors: %bb.1(0x40000000)
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# CHECK: liveins: $edi
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# CHECK: CMP32ri8 killed $edi, 2, implicit-def $eflags
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# CHECK: TCRETURNdi64cc @mergeable_conditional_tailcall
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# This was the unconditional branch to a dead MBB that we left behind before
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# this bug was fixed.
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# CHECK-NOT: JMP_1 %bb.-1
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--- |
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; ModuleID = 't.ll'
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source_filename = "t.ll"
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target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
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target triple = "x86_64--linux"
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@static_local_guard = external global i64, align 8
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; Function Attrs: optsize
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define void @f(i32 %arg) #0 {
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entry:
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switch i32 %arg, label %sw.epilog [
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i32 0, label %sw.bb
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i32 1, label %sw.bb
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i32 2, label %sw.bb2
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]
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sw.bb: ; preds = %entry, %entry
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%tmp = load atomic i8, i8* bitcast (i64* @static_local_guard to i8*) acquire, align 8
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%guard.uninitialized.i = icmp eq i8 %tmp, 0
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br i1 %guard.uninitialized.i, label %init.check.i, label %return, !prof !0
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init.check.i: ; preds = %sw.bb
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tail call void @initialize_static_local(i64* nonnull @static_local_guard)
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ret void
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sw.bb2: ; preds = %entry
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tail call void @mergeable_conditional_tailcall()
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ret void
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sw.epilog: ; preds = %entry
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tail call void @mergeable_conditional_tailcall()
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ret void
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return: ; preds = %sw.bb
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ret void
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}
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declare void @mergeable_conditional_tailcall()
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declare void @initialize_static_local(i64*)
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; Function Attrs: nounwind
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declare void @llvm.stackprotector(i8*, i8**) #1
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attributes #0 = { optsize }
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attributes #1 = { nounwind }
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!0 = !{!"branch_weights", i32 1, i32 1048575}
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...
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---
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name: f
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alignment: 0
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exposesReturnsTwice: false
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legalized: false
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regBankSelected: false
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selected: false
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tracksRegLiveness: true
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registers:
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liveins:
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- { reg: '$edi', virtual-reg: '' }
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frameInfo:
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isFrameAddressTaken: false
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isReturnAddressTaken: false
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hasStackMap: false
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hasPatchPoint: false
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stackSize: 0
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offsetAdjustment: 0
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maxAlignment: 0
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adjustsStack: false
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hasCalls: false
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stackProtector: ''
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maxCallFrameSize: 0
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hasOpaqueSPAdjustment: false
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hasVAStart: false
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hasMustTailInVarArgFunc: false
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savePoint: ''
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restorePoint: ''
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fixedStack:
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stack:
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constants:
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body: |
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bb.0.entry:
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successors: %bb.2(0x40000000), %bb.1(0x40000000)
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liveins: $edi
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CMP32ri8 killed $edi, 2, implicit-def $eflags
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JB_1 %bb.2, implicit $eflags
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JMP_1 %bb.1
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bb.1.entry:
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successors: %bb.4(0x40000000), %bb.5(0x40000000)
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liveins: $eflags
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JE_1 %bb.4, implicit killed $eflags
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JMP_1 %bb.5
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bb.2.sw.bb:
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successors: %bb.3(0x00000800), %bb.6(0x7ffff800)
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$al = MOV8rm $rip, 1, $noreg, @static_local_guard, $noreg :: (volatile load acquire 1 from `i8* bitcast (i64* @static_local_guard to i8*)`, align 8)
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TEST8rr killed $al, $al, implicit-def $eflags
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JNE_1 %bb.6, implicit killed $eflags
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JMP_1 %bb.3
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bb.3.init.check.i:
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dead $edi = MOV32ri @static_local_guard, implicit-def $rdi
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TCRETURNdi64 @initialize_static_local, 0, csr_64, implicit $rsp, implicit $rdi
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bb.4.sw.bb2:
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TCRETURNdi64 @mergeable_conditional_tailcall, 0, csr_64, implicit $rsp
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bb.5.sw.epilog:
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TCRETURNdi64 @mergeable_conditional_tailcall, 0, csr_64, implicit $rsp
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bb.6.return:
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RET 0
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...
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