[DAG] getCarry - always succeed if we encounter a i1 type during trunc/ext peeling #169777
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…c/ext peeling If we are reconstructing a carry from a raw MVT::i1 type, make sure we don't miss any cases while peeling through trunc/ext chains - check for i1 types at the start of the while loop Fixes llvm#169691
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@llvm/pr-subscribers-backend-x86 @llvm/pr-subscribers-llvm-selectiondag Author: Simon Pilgrim (RKSimon) ChangesIf we are force reconstructing a carry from a raw MVT::i1 type, make sure we don't miss any cases while peeling through trunc/ext chains - check for i1 types at the start of the while loop Fixes #169691 Full diff: https://github.com/llvm/llvm-project/pull/169777.diff 2 Files Affected:
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 6b79dbb46cadc..0f3a207cc6414 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -3288,6 +3288,9 @@ static SDValue getAsCarry(const TargetLowering &TLI, SDValue V,
// First, peel away TRUNCATE/ZERO_EXTEND/AND nodes due to legalization.
while (true) {
+ if (ForceCarryReconstruction && V.getValueType() == MVT::i1)
+ return V;
+
if (V.getOpcode() == ISD::TRUNCATE || V.getOpcode() == ISD::ZERO_EXTEND) {
V = V.getOperand(0);
continue;
@@ -3302,9 +3305,6 @@ static SDValue getAsCarry(const TargetLowering &TLI, SDValue V,
continue;
}
- if (ForceCarryReconstruction && V.getValueType() == MVT::i1)
- return V;
-
break;
}
diff --git a/llvm/test/CodeGen/X86/addcarry.ll b/llvm/test/CodeGen/X86/addcarry.ll
index f8a04f8514988..ee4482062df31 100644
--- a/llvm/test/CodeGen/X86/addcarry.ll
+++ b/llvm/test/CodeGen/X86/addcarry.ll
@@ -1517,18 +1517,9 @@ define i1 @pr84831(i64 %arg) {
define void @pr169691(ptr %p0, i64 %implicit, i1 zeroext %carry) {
; CHECK-LABEL: pr169691:
; CHECK: # %bb.0:
-; CHECK-NEXT: movq (%rdi), %rax
-; CHECK-NEXT: addq %rsi, %rax
-; CHECK-NEXT: setb %cl
-; CHECK-NEXT: movl %edx, %edx
-; CHECK-NEXT: addq %rax, %rdx
-; CHECK-NEXT: setb %al
-; CHECK-NEXT: orb %cl, %al
-; CHECK-NEXT: movq %rdx, (%rdi)
-; CHECK-NEXT: addq 8(%rdi), %rsi
-; CHECK-NEXT: movzbl %al, %eax
-; CHECK-NEXT: addq %rsi, %rax
-; CHECK-NEXT: movq %rax, 8(%rdi)
+; CHECK-NEXT: addb $-1, %dl
+; CHECK-NEXT: adcq %rsi, (%rdi)
+; CHECK-NEXT: adcq %rsi, 8(%rdi)
; CHECK-NEXT: retq
%a0 = load i64, ptr %p0, align 8
%uaddo0 = call { i64, i1 } @llvm.uadd.with.overflow.i64(i64 %a0, i64 %implicit)
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arsenm
approved these changes
Nov 30, 2025
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/211/builds/4185 Here is the relevant piece of the build log for the reference |
Collaborator
|
LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/95/builds/19274 Here is the relevant piece of the build log for the reference |
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…c/ext peeling (llvm#169777) If we are force reconstructing a carry from a raw MVT::i1 type, make sure we don't miss any cases while peeling through trunc/ext chains - check for i1 types at the start of the while loop Fixes llvm#169691
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…c/ext peeling (llvm#169777) If we are force reconstructing a carry from a raw MVT::i1 type, make sure we don't miss any cases while peeling through trunc/ext chains - check for i1 types at the start of the while loop Fixes llvm#169691
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…c/ext peeling (llvm#169777) If we are force reconstructing a carry from a raw MVT::i1 type, make sure we don't miss any cases while peeling through trunc/ext chains - check for i1 types at the start of the while loop Fixes llvm#169691
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…c/ext peeling (llvm#169777) If we are force reconstructing a carry from a raw MVT::i1 type, make sure we don't miss any cases while peeling through trunc/ext chains - check for i1 types at the start of the while loop Fixes llvm#169691
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If we are force reconstructing a carry from a raw MVT::i1 type, make sure we don't miss any cases while peeling through trunc/ext chains - check for i1 types at the start of the while loop
Fixes #169691