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[BOLT][RISCV] Carry-over annotations when fixing calls #66763

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Merged
merged 2 commits into from
Sep 21, 2023
Merged

[BOLT][RISCV] Carry-over annotations when fixing calls #66763

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52fb718
[BOLT][RISCV] Carry-over annotations when fixing calls
mtvec Sep 19, 2023
7b81499
Expand `auto`s
mtvec Sep 21, 2023
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2 changes: 1 addition & 1 deletion bolt/include/bolt/Core/MCPlusBuilder.h
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Original file line number Diff line number Diff line change
Expand Up @@ -170,6 +170,7 @@ class MCPlusBuilder {
/// MCPlusBuilder classes must use convert/lower/create* interfaces instead.
void setTailCall(MCInst &Inst);

public:
/// Transfer annotations from \p SrcInst to \p DstInst.
void moveAnnotations(MCInst &&SrcInst, MCInst &DstInst) const {
assert(!getAnnotationInst(DstInst) &&
Expand All @@ -182,7 +183,6 @@ class MCPlusBuilder {
removeAnnotationInst(SrcInst);
}

public:
/// Return iterator range covering def operands.
iterator_range<MCInst::iterator> defOperands(MCInst &Inst) const {
return make_range(Inst.begin(),
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13 changes: 13 additions & 0 deletions bolt/lib/Passes/FixRISCVCallsPass.cpp
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Expand Up @@ -19,13 +19,15 @@ void FixRISCVCallsPass::runOnFunction(BinaryFunction &BF) {
auto *Target = MIB->getTargetSymbol(*II);
assert(Target && "Cannot find call target");

MCInst OldCall = *II;
auto L = BC.scopeLock();

if (MIB->isTailCall(*II))
MIB->createTailCall(*II, Target, Ctx);
else
MIB->createCall(*II, Target, Ctx);

MIB->moveAnnotations(std::move(OldCall), *II);
++II;
continue;
}
Expand All @@ -39,8 +41,19 @@ void FixRISCVCallsPass::runOnFunction(BinaryFunction &BF) {
auto *Target = MIB->getTargetSymbol(*II);
assert(Target && "Cannot find call target");

MCInst OldCall = *NextII;
auto L = BC.scopeLock();
MIB->createCall(*II, Target, Ctx);
MIB->moveAnnotations(std::move(OldCall), *II);

// The original offset was set on the jalr of the auipc+jalr pair. Since
// the whole pair is replaced by a call, adjust the offset by -4 (the
// size of a auipc).
if (std::optional<uint32_t> Offset = MIB->getOffset(*II)) {
assert(*Offset >= 4 && "Illegal jalr offset");
MIB->setOffset(*II, *Offset - 4);
}

II = BB.eraseInstruction(NextII);
continue;
}
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33 changes: 33 additions & 0 deletions bolt/test/RISCV/call-annotations.s
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@@ -0,0 +1,33 @@
/// Test that annotations are properly carried over to fixed calls.
/// Note that --enable-bat is used to force offsets to be kept.

// RUN: llvm-mc -triple riscv64 -filetype obj -o %t.o %s
// RUN: ld.lld --emit-relocs -o %t %t.o
// RUN: llvm-bolt --enable-bat --print-cfg --print-fix-riscv-calls \
// RUN: --print-only=_start -o /dev/null %t | FileCheck %s

.text
.global f
.p2align 1
f:
ret
.size f, .-f

// CHECK-LABEL: Binary Function "_start" after building cfg {
// CHECK: auipc ra, f
// CHECK-NEXT: jalr ra, -4(ra) # Offset: 4
// CHECK-NEXT: jal ra, f # Offset: 8
// CHECK-NEXT: jal zero, f # TAILCALL # Offset: 12

// CHECK-LABEL: Binary Function "_start" after fix-riscv-calls {
// CHECK: call f # Offset: 0
// CHECK-NEXT: call f # Offset: 8
// CHECK-NEXT: tail f # TAILCALL # Offset: 12

.globl _start
.p2align 1
_start:
call f
jal f
jal zero, f
.size _start, .-_start