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[InstCombine] Propagate Profile when Folding Implied Conditionals #163412

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Merged
merged 2 commits into from
Oct 14, 2025
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[InstCombine] Propagate Profile when Folding Implied Conditionals #163412

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[InstCombine] Propagate Profile when Folding Implied Conditionals
boomanaiden154 Oct 14, 2025
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boomanaiden154 Oct 14, 2025
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12 changes: 8 additions & 4 deletions llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2979,10 +2979,14 @@ Instruction *InstCombinerImpl::foldAndOrOfSelectUsingImpliedCond(Value *Op,
"Op must be either i1 or vector of i1.");
if (SI.getCondition()->getType() != Op->getType())
return nullptr;
if (Value *V = simplifyNestedSelectsUsingImpliedCond(SI, Op, IsAnd, DL))
return SelectInst::Create(Op,
IsAnd ? V : ConstantInt::getTrue(Op->getType()),
IsAnd ? ConstantInt::getFalse(Op->getType()) : V);
if (Value *V = simplifyNestedSelectsUsingImpliedCond(SI, Op, IsAnd, DL)) {
Instruction *MDFrom = nullptr;
if (!ProfcheckDisableMetadataFixes)
MDFrom = &SI;
return SelectInst::Create(
Op, IsAnd ? V : ConstantInt::getTrue(Op->getType()),
IsAnd ? ConstantInt::getFalse(Op->getType()) : V, "", nullptr, MDFrom);
}
return nullptr;
}

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15 changes: 11 additions & 4 deletions llvm/test/Transforms/InstCombine/select-safe-impliedcond-transforms.ll
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@@ -1,4 +1,4 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals
; RUN: opt < %s -passes=instcombine -S | FileCheck %s

define i1 @a_true_implies_b_true(i8 %z, i1 %X, i1 %Y) {
Expand Down Expand Up @@ -34,15 +34,15 @@ define <2 x i1> @a_true_implies_b_true_vec(i8 %z0, <2 x i1> %X, <2 x i1> %Y) {
ret <2 x i1> %res
}

define i1 @a_true_implies_b_true2(i8 %z, i1 %X, i1 %Y) {
define i1 @a_true_implies_b_true2(i8 %z, i1 %X, i1 %Y) !prof !0 {
; CHECK-LABEL: @a_true_implies_b_true2(
; CHECK-NEXT: [[A:%.*]] = icmp ugt i8 [[Z:%.*]], 20
; CHECK-NEXT: [[RES:%.*]] = select i1 [[A]], i1 [[X:%.*]], i1 false
; CHECK-NEXT: [[RES:%.*]] = select i1 [[A]], i1 [[X:%.*]], i1 false, !prof [[PROF1:![0-9]+]]
; CHECK-NEXT: ret i1 [[RES]]
;
%a = icmp ugt i8 %z, 20
%b = icmp ugt i8 %z, 10
%sel = select i1 %b, i1 %X, i1 %Y
%sel = select i1 %b, i1 %X, i1 %Y, !prof !1
%res = and i1 %a, %sel
ret i1 %res
}
Expand Down Expand Up @@ -258,3 +258,10 @@ define i1 @neg_icmp_eq_implies_trunc(i8 %x, i1 %c) {
%sel2 = select i1 %cmp, i1 true, i1 %sel1
ret i1 %sel2
}

!0 = !{!"function_entry_count", i64 1000}
!1 = !{!"branch_weights", i32 2, i32 3}
;.
; CHECK: [[META0:![0-9]+]] = !{!"function_entry_count", i64 1000}
; CHECK: [[PROF1]] = !{!"branch_weights", i32 2, i32 3}
;.
2 changes: 0 additions & 2 deletions llvm/utils/profcheck-xfail.txt
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Expand Up @@ -906,7 +906,6 @@ Transforms/InstCombine/select_frexp.ll
Transforms/InstCombine/select.ll
Transforms/InstCombine/select-min-max.ll
Transforms/InstCombine/select-of-symmetric-selects.ll
Transforms/InstCombine/select-safe-impliedcond-transforms.ll
Transforms/InstCombine/select-safe-transforms.ll
Transforms/InstCombine/select-select.ll
Transforms/InstCombine/select-with-extreme-eq-cond.ll
Expand Down Expand Up @@ -1237,7 +1236,6 @@ Transforms/PartiallyInlineLibCalls/X86/good-prototype.ll
Transforms/PGOProfile/chr-dead-pred.ll
Transforms/PGOProfile/chr-dup-threshold.ll
Transforms/PGOProfile/chr-lifetimes.ll
Transforms/PGOProfile/chr.ll
Transforms/PGOProfile/chr-poison.ll
Transforms/PGOProfile/comdat.ll
Transforms/PGOProfile/memop_profile_funclet_wasm.ll
Expand Down