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[BOLT] Preserve Offset annotation in fixDoubleJumps (#91898)

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Offset annotation was missed when optimizing an unconditional branch to
a tail call.

Test Plan: update bb-with-two-tail-calls.s
This commit is contained in:
Amir Ayupov 2024-05-12 14:26:41 -07:00
parent a037d88929
commit 54b17fa4ee
2 changed files with 6 additions and 3 deletions
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3
bolt/lib/Passes/BinaryPasses.cpp
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@ -715,6 +715,9 @@ static uint64_t fixDoubleJumps(BinaryFunction &Function, bool MarkInvalid) {
Pred->removeSuccessor(&BB);
Pred->eraseInstruction(Pred->findInstruction(Branch));
Pred->addTailCallInstruction(SuccSym);
MCInst *TailCall = Pred->getLastNonPseudoInstr();
assert(TailCall);
MIB->setOffset(*TailCall, BB.getOffset());
} else {
return false;
}

6
bolt/test/X86/bb-with-two-tail-calls.s
View File

@ -9,11 +9,11 @@
# RUN: llvm-strip --strip-unneeded %t.o
# RUN: %clang %cflags %t.o -o %t.exe -Wl,-q -nostdlib
# RUN: llvm-bolt %t.exe -o %t.out --data %t.fdata --lite=0 --dyno-stats \
# RUN: --print-sctc --print-only=_start 2>&1 | FileCheck %s
# RUN: --print-sctc --print-only=_start -enable-bat 2>&1 | FileCheck %s
# CHECK-NOT: Assertion `BranchInfo.size() == 2 && "could only be called for blocks with 2 successors"' failed.
# Two tail calls in the same basic block after SCTC:
# CHECK: {{.*}}: ja {{.*}} # TAILCALL # CTCTakenCount: {{.*}}
# CHECK-NEXT: {{.*}}: jmp {{.*}} # TAILCALL
# CHECK: {{.*}}: ja {{.*}} # TAILCALL # Offset: 7 # CTCTakenCount: 4
# CHECK-NEXT: {{.*}}: jmp {{.*}} # TAILCALL # Offset: 12
.globl _start
_start: