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[CGP] Fix matching of uadd overflow #626

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[CGP] Fix matching of uadd overflow #626

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25b4315
[CGP] Add pre-commit test for Fix matching of uadd overflow
vladimirradosavljevic Jun 18, 2024
098d481
[CGP] Fix matching of uadd overflow
vladimirradosavljevic Jun 18, 2024
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4 changes: 3 additions & 1 deletion llvm/lib/CodeGen/CodeGenPrepare.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1584,7 +1584,9 @@ static bool matchUAddWithOverflowConstantEdgeCases(CmpInst *Cmp,
if (Pred == ICmpInst::ICMP_EQ && match(B, m_AllOnes()))
B = ConstantInt::get(B->getType(), 1);
else if (Pred == ICmpInst::ICMP_NE && match(B, m_ZeroInt()))
B = ConstantInt::get(B->getType(), -1);
// EraVM local begin
B = ConstantInt::get(B->getType(), -1, true);
// EraVM local end
else
return false;

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55 changes: 55 additions & 0 deletions llvm/test/CodeGen/EraVM/cgp-uadd-overflow-wrong-match.ll
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@@ -0,0 +1,55 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
; RUN: opt -codegenprepare --cgp-verify-bfi-updates=false -S < %s | FileCheck %s
; Verification of BFI updates is disabled because of https://github.com/llvm/llvm-project/issues/64197

target datalayout = "E-p:256:256-i256:256:256-S32-a:256:256"
target triple = "eravm"

define i256 @dont_match(i256 %a) {
; CHECK-LABEL: define i256 @dont_match
; CHECK-SAME: (i256 [[A:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: [[ADD:%.*]] = add i256 [[A]], 18446744073709551615
; CHECK-NEXT: [[CMP:%.*]] = icmp ne i256 [[A]], 0
; CHECK-NEXT: br i1 [[CMP]], label [[THEN:%.*]], label [[ELSE:%.*]]
; CHECK: then:
; CHECK-NEXT: ret i256 0
; CHECK: else:
; CHECK-NEXT: ret i256 [[ADD]]
;
entry:
%add = add i256 %a, 18446744073709551615
%cmp = icmp ne i256 %a, 0
br i1 %cmp, label %then, label %else

then:
ret i256 0

else:
ret i256 %add
}

define i256 @match(i256 %a) {
; CHECK-LABEL: define i256 @match
; CHECK-SAME: (i256 [[A:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: [[TMP0:%.*]] = call { i256, i1 } @llvm.uadd.with.overflow.i256(i256 [[A]], i256 -1)
; CHECK-NEXT: [[MATH:%.*]] = extractvalue { i256, i1 } [[TMP0]], 0
; CHECK-NEXT: [[OV:%.*]] = extractvalue { i256, i1 } [[TMP0]], 1
; CHECK-NEXT: br i1 [[OV]], label [[THEN:%.*]], label [[ELSE:%.*]]
; CHECK: then:
; CHECK-NEXT: ret i256 0
; CHECK: else:
; CHECK-NEXT: ret i256 [[MATH]]
;
entry:
%add = add i256 %a, -1
%cmp = icmp ne i256 %a, 0
br i1 %cmp, label %then, label %else

then:
ret i256 0

else:
ret i256 %add
}