Skip to content

[RISCV] Don't delete all fixups in RISCVMCCodeEmitter::expandLongCondBr. #109513

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Sep 23, 2024
Merged

[RISCV] Don't delete all fixups in RISCVMCCodeEmitter::expandLongCondBr. #109513

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
9b05a6f
[RISCV} Don't delete all fixups in RISCVMCCodeEmitter::expandLongCondBr.
topperc Sep 21, 2024
de87c27
fixup! address review comments.
topperc Sep 22, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 6 additions & 1 deletion llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCCodeEmitter.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -283,13 +283,18 @@ void RISCVMCCodeEmitter::expandLongCondBr(const MCInst &MI,
Offset = 4;
}

// Save the number fixups.
size_t N = Fixups.size();
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Perhaps FixupStartIndex to be similar to MCELFStreamer.cpp:550


// Emit an unconditional jump to the destination.
MCInst TmpInst =
MCInstBuilder(RISCV::JAL).addReg(RISCV::X0).addOperand(SrcSymbol);
uint32_t Binary = getBinaryCodeForInstr(TmpInst, Fixups, STI);
support::endian::write(CB, Binary, llvm::endianness::little);

Fixups.clear();
// Drop any fixup added so we can add the correct one.
Fixups.resize(N);

if (SrcSymbol.isExpr()) {
Fixups.push_back(MCFixup::create(Offset, SrcSymbol.getExpr(),
MCFixupKind(RISCV::fixup_riscv_jal),
Expand Down
19 changes: 19 additions & 0 deletions llvm/test/MC/RISCV/long-conditional-jump-crash.s
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,19 @@
# RUN: llvm-mc %s -mc-relax-all -triple=riscv64 -filetype=obj \
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

llvm/test/MC/RISCV/rv64-relax-all.s tests -mc-relax-all. Add the test there, perhaps rename the file?

# RUN: | llvm-objdump -d -M no-aliases - \
# RUN: | FileCheck --check-prefix=CHECK %s

# This test previously crashed because expanding a conditional branch deleted
# all fixups in the fragment.

# CHECK: beq s0, zero, 0x8
# CHECK-NEXT: jal zero, 0x14
# CHECK-NEXT: jal zero, 0x14
# CHECK-NEXT: bne s0, zero, 0x14
# CHECK-NEXT: jal zero, 0x14

# CHECK: jalr zero, 0x0(ra)
bnez s0, .foo
j .foo
beqz s0, .foo
.foo:
ret
Loading