release/20.x: [Hexagon] Explicitly truncate constant in UAddSubO (#127360) #127527
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
|
@topperc What do you think about merging this PR to the release branch? |
|
@llvm/pr-subscribers-backend-hexagon Author: None (llvmbot) ChangesBackport 788cb72 Requested by: @nikic Full diff: https://github.com/llvm/llvm-project/pull/127527.diff 2 Files Affected:
diff --git a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
index 12ca0c505bd06..5ce5cae2ff906 100644
--- a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
@@ -3273,7 +3273,7 @@ HexagonTargetLowering::LowerUAddSubO(SDValue Op, SelectionDAG &DAG) const {
if (Opc == ISD::USUBO) {
SDValue Op = DAG.getNode(ISD::SUB, dl, VTs.VTs[0], {X, Y});
SDValue Ov = DAG.getSetCC(dl, MVT::i1, Op,
- DAG.getConstant(-1, dl, ty(Op)), ISD::SETEQ);
+ DAG.getAllOnesConstant(dl, ty(Op)), ISD::SETEQ);
return DAG.getMergeValues({Op, Ov}, dl);
}
}
diff --git a/llvm/test/CodeGen/Hexagon/iss127296.ll b/llvm/test/CodeGen/Hexagon/iss127296.ll
new file mode 100644
index 0000000000000..bf0e7a9881014
--- /dev/null
+++ b/llvm/test/CodeGen/Hexagon/iss127296.ll
@@ -0,0 +1,18 @@
+; RUN: llc -mtriple=hexagon -O0 < %s | FileCheck %s
+
+; CHECK: r0 = add(r0,#-1)
+
+define fastcc void @os.linux.tls.initStatic(i32 %x) {
+ %1 = call { i32, i1 } @llvm.usub.with.overflow.i32(i32 %x, i32 1)
+ br label %2
+
+ 2: ; preds = %0
+ %3 = extractvalue { i32, i1 } %1, 0
+ ret void
+}
+
+; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
+declare { i32, i1 } @llvm.usub.with.overflow.i32(i32, i32) #0
+
+attributes #0 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
+
|
After llvm#117558 landed, this code would assert "Value is not an N-bit unsigned value" in getConstant(), from a test case in zig. Co-authored-by: Craig Topper <craig.topper@sifive.com> Fixes llvm#127296 (cherry picked from commit 788cb72)
|
@nikic (or anyone else). If you would like to add a note about this fix in the release notes (completely optional). Please reply to this comment with a one or two sentence description of the fix. When you are done, please add the release:note label to this PR. |
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 788cb72
Requested by: @nikic