[RISCV] Correct the CFA offsets for stack probing.#166616
Merged
Conversation
We need to take into account that we already did a FirstSPAdjust. Fixes llvm#164805.
Member
|
@llvm/pr-subscribers-backend-risc-v Author: Craig Topper (topperc) ChangesWe need to take into account that we already did a FirstSPAdjust. Fixes #164805. 2 Files Affected:
diff --git a/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp b/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
index b37b7405a660f..f881c4c79d444 100644
--- a/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
@@ -789,6 +789,8 @@ void RISCVFrameLowering::allocateStack(MachineBasicBlock &MBB,
// Unroll the probe loop depending on the number of iterations.
if (Offset < ProbeSize * 5) {
+ uint64_t CFAAdjust = RealStackSize - Offset;
+
uint64_t CurrentOffset = 0;
while (CurrentOffset + ProbeSize <= Offset) {
RI->adjustReg(MBB, MBBI, DL, SPReg, SPReg,
@@ -802,7 +804,7 @@ void RISCVFrameLowering::allocateStack(MachineBasicBlock &MBB,
CurrentOffset += ProbeSize;
if (EmitCFI)
- CFIBuilder.buildDefCFAOffset(CurrentOffset);
+ CFIBuilder.buildDefCFAOffset(CurrentOffset + CFAAdjust);
}
uint64_t Residual = Offset - CurrentOffset;
@@ -810,7 +812,7 @@ void RISCVFrameLowering::allocateStack(MachineBasicBlock &MBB,
RI->adjustReg(MBB, MBBI, DL, SPReg, SPReg,
StackOffset::getFixed(-Residual), Flag, getStackAlign());
if (EmitCFI)
- CFIBuilder.buildDefCFAOffset(Offset);
+ CFIBuilder.buildDefCFAOffset(RealStackSize);
if (DynAllocation) {
// s[d|w] zero, 0(sp)
diff --git a/llvm/test/CodeGen/RISCV/rvv/stack-probing-dynamic.ll b/llvm/test/CodeGen/RISCV/rvv/stack-probing-dynamic.ll
index d666832cf6e0b..c79fb0f91b21f 100644
--- a/llvm/test/CodeGen/RISCV/rvv/stack-probing-dynamic.ll
+++ b/llvm/test/CodeGen/RISCV/rvv/stack-probing-dynamic.ll
@@ -460,9 +460,9 @@ define void @reserved_call_frame(i64 %n) #0 {
; RV64I-NEXT: lui a0, 1
; RV64I-NEXT: sub sp, sp, a0
; RV64I-NEXT: sd zero, 0(sp)
-; RV64I-NEXT: .cfi_def_cfa_offset 4096
+; RV64I-NEXT: .cfi_def_cfa_offset 6128
; RV64I-NEXT: addi sp, sp, -48
-; RV64I-NEXT: .cfi_def_cfa_offset 4144
+; RV64I-NEXT: .cfi_def_cfa_offset 6176
; RV64I-NEXT: lui a0, 1
; RV64I-NEXT: add a0, sp, a0
; RV64I-NEXT: call callee_stack_args
@@ -485,9 +485,9 @@ define void @reserved_call_frame(i64 %n) #0 {
; RV32I-NEXT: lui a0, 1
; RV32I-NEXT: sub sp, sp, a0
; RV32I-NEXT: sw zero, 0(sp)
-; RV32I-NEXT: .cfi_def_cfa_offset 4096
+; RV32I-NEXT: .cfi_def_cfa_offset 6128
; RV32I-NEXT: addi sp, sp, -80
-; RV32I-NEXT: .cfi_def_cfa_offset 4176
+; RV32I-NEXT: .cfi_def_cfa_offset 6208
; RV32I-NEXT: lui a0, 1
; RV32I-NEXT: addi a0, a0, 36
; RV32I-NEXT: add a0, sp, a0
|
ilovepi
approved these changes
Nov 6, 2025
s-barannikov
approved these changes
Nov 6, 2025
Contributor
s-barannikov
left a comment
s-barannikov
left a comment
There was a problem hiding this comment.
The changes to the test look correct, but I'm not very familiar with the implementation.
dyung
pushed a commit
to llvmbot/llvm-project
that referenced
this pull request
Nov 12, 2025
We need to take into account that we may have already done a FirstSPAdjust. Fixes llvm#164805. (cherry picked from commit ff11b93)
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
5 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
We need to take into account that we already did a FirstSPAdjust.
Fixes #164805.