-
Notifications
You must be signed in to change notification settings - Fork 10.8k
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.
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
release/18.x: [RISCV] Make sure ADDI replacement in optimizeCondBranch has a virtual reg destination. (#81938) #81953
Merged
Conversation
This file contains 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
@mshockwave What do you think about merging this PR to the release branch? |
@llvm/pr-subscribers-backend-risc-v Author: None (llvmbot) ChangesBackport feee627 Requested by: @topperc Full diff: https://github.com/llvm/llvm-project/pull/81953.diff 2 Files Affected:
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
index 592962cebe8973..d5b1ddfbeb3dc9 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
@@ -1229,7 +1229,8 @@ bool RISCVInstrInfo::optimizeCondBranch(MachineInstr &MI) const {
MachineBasicBlock::reverse_iterator II(&MI), E = MBB->rend();
auto DefC1 = std::find_if(++II, E, [&](const MachineInstr &I) -> bool {
int64_t Imm;
- return isLoadImm(&I, Imm) && Imm == C1;
+ return isLoadImm(&I, Imm) && Imm == C1 &&
+ I.getOperand(0).getReg().isVirtual();
});
if (DefC1 != E)
return DefC1->getOperand(0).getReg();
diff --git a/llvm/test/CodeGen/RISCV/branch-opt.mir b/llvm/test/CodeGen/RISCV/branch-opt.mir
new file mode 100644
index 00000000000000..ba3a20f2fbfcd3
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/branch-opt.mir
@@ -0,0 +1,68 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 4
+# RUN: llc %s -mtriple=riscv64 -run-pass=peephole-opt -o - | FileCheck %s
+
+# Make sure we shouldn't replace the %2 ADDI with the $x10 ADDI since it has a
+# physical register destination.
+
+--- |
+ define void @foo(i32 signext %0) {
+ tail call void @bar(i32 1)
+ %2 = icmp ugt i32 %0, 1
+ br i1 %2, label %3, label %4
+
+ 3: ; preds = %1
+ tail call void @bar(i32 3)
+ ret void
+
+ 4: ; preds = %1
+ ret void
+ }
+
+ declare void @bar(...)
+
+...
+---
+name: foo
+tracksRegLiveness: true
+body: |
+ ; CHECK-LABEL: name: foo
+ ; CHECK: bb.0 (%ir-block.1):
+ ; CHECK-NEXT: successors: %bb.1(0x40000000), %bb.2(0x40000000)
+ ; CHECK-NEXT: liveins: $x10
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: [[COPY:%[0-9]+]]:gpr = COPY $x10
+ ; CHECK-NEXT: ADJCALLSTACKDOWN 0, 0, implicit-def dead $x2, implicit $x2
+ ; CHECK-NEXT: $x10 = ADDI $x0, 1
+ ; CHECK-NEXT: PseudoCALL target-flags(riscv-call) @bar, csr_ilp32_lp64, implicit-def dead $x1, implicit $x10, implicit-def $x2
+ ; CHECK-NEXT: ADJCALLSTACKUP 0, 0, implicit-def dead $x2, implicit $x2
+ ; CHECK-NEXT: [[ADDI:%[0-9]+]]:gpr = ADDI $x0, 2
+ ; CHECK-NEXT: BLTU [[COPY]], killed [[ADDI]], %bb.2
+ ; CHECK-NEXT: PseudoBR %bb.1
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.1 (%ir-block.3):
+ ; CHECK-NEXT: $x10 = ADDI $x0, 3
+ ; CHECK-NEXT: PseudoTAIL target-flags(riscv-call) @bar, implicit $x2, implicit $x10
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.2 (%ir-block.4):
+ ; CHECK-NEXT: PseudoRET
+ bb.0 (%ir-block.1):
+ successors: %bb.1, %bb.2
+ liveins: $x10
+
+ %0:gpr = COPY $x10
+ ADJCALLSTACKDOWN 0, 0, implicit-def dead $x2, implicit $x2
+ $x10 = ADDI $x0, 1
+ PseudoCALL target-flags(riscv-call) @bar, csr_ilp32_lp64, implicit-def dead $x1, implicit $x10, implicit-def $x2
+ ADJCALLSTACKUP 0, 0, implicit-def dead $x2, implicit $x2
+ %2:gpr = ADDI $x0, 2
+ BLTU %0, killed %2, %bb.2
+ PseudoBR %bb.1
+
+ bb.1 (%ir-block.3):
+ $x10 = ADDI $x0, 3
+ PseudoTAIL target-flags(riscv-call) @bar, implicit $x2, implicit $x10
+
+ bb.2 (%ir-block.4):
+ PseudoRET
+
+...
|
mshockwave
approved these changes
Feb 16, 2024
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
LGTM
…l reg destination. (llvm#81938) If it isn't virtual, we may extend the live range of the physical register past were it is valid. For example, across a call. Found while trying to enable -riscv-enable-sink-fold which enables some copy propagation in machine sink that led to ADDIs with physical register destinations. (cherry picked from commit feee627)
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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.
Backport feee627
Requested by: @topperc