ab6876a40d
Since D129288, callbr is allowed to have duplicate successors. This patch removes a limitation which prevents optimizations from actually producing such callbrs.
This is probably the riskiest of all the recent callbr changes, because code with incorrect assumptions might be lurking somewhere. I fixed the one case I encountered ahead of time in 8201e3ef5c.
Reviewed By: nickdesaulniers
Differential Revision: https://reviews.llvm.org/D129997
Originally landed as
commit 08860f525a23 ("[Local] Allow creating callbr with duplicate successors")
Reverted in
commit 1cf6b93df168 ("Revert "[Local] Allow creating callbr with duplicate successors"")
60 lines
1.4 KiB
LLVM
60 lines
1.4 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt < %s -S -simplifycfg -simplifycfg-require-and-preserve-domtree=1 | FileCheck %s
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define void @callbr_duplicate_dest() {
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; CHECK-LABEL: @callbr_duplicate_dest(
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; CHECK-NEXT: entry:
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; CHECK-NEXT: callbr void asm sideeffect "", "!i"()
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; CHECK-NEXT: to label [[BB:%.*]] [label %bb]
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; CHECK: bb:
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; CHECK-NEXT: ret void
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;
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entry:
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callbr void asm sideeffect "", "!i"()
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to label %bb [label %bb]
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bb:
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ret void
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}
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define void @callbr_can_fold_to_duplicate_dest1() {
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; CHECK-LABEL: @callbr_can_fold_to_duplicate_dest1(
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; CHECK-NEXT: entry:
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; CHECK-NEXT: callbr void asm sideeffect "", "!i"()
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; CHECK-NEXT: to label [[COMMON_RET:%.*]] [label %common.ret]
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; CHECK: common.ret:
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; CHECK-NEXT: ret void
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;
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entry:
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callbr void asm sideeffect "", "!i"()
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to label %bb2 [label %bb1]
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bb1:
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ret void
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bb2:
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ret void
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}
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define void @callbr_can_fold_to_duplicate_dest2() {
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; CHECK-LABEL: @callbr_can_fold_to_duplicate_dest2(
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; CHECK-NEXT: entry:
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; CHECK-NEXT: callbr void asm sideeffect "", "!i,!i"()
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; CHECK-NEXT: to label [[COMMON_RET:%.*]] [label [[COMMON_RET]], label %common.ret]
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; CHECK: common.ret:
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; CHECK-NEXT: ret void
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;
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entry:
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callbr void asm sideeffect "", "!i,!i"()
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to label %bb1 [label %bb2, label %bb3]
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bb1:
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ret void
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bb2:
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ret void
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bb3:
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ret void
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}
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