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[CVP] Infer nuw/nsw flags for TruncInst #130504

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Merged
merged 4 commits into from
Mar 12, 2025
Merged

[CVP] Infer nuw/nsw flags for TruncInst #130504

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115fc72
Add Test
veera-sivarajan Mar 9, 2025
703460b
[CVP] Infer `nuw`/`nsw` Flags for TruncInst
veera-sivarajan Mar 9, 2025
c74e9b6
Add Test for Assume
veera-sivarajan Mar 10, 2025
bdf2473
Update Clang Codegen Test and Remove Unnecessary XORs
veera-sivarajan Mar 11, 2025
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2 changes: 1 addition & 1 deletion clang/test/CodeGen/attr-counted-by.c
View file
Original file line number Diff line number Diff line change
@@ -333,7 +333,7 @@ size_t test3_bdos(struct annotated *p) {
// SANITIZE-WITH-ATTR-NEXT: [[COUNT50:%.*]] = sext i32 [[DOTCOUNTED_BY_LOAD44]] to i64
// SANITIZE-WITH-ATTR-NEXT: [[TMP10:%.*]] = sub nsw i64 [[COUNT50]], [[IDXPROM42]]
// SANITIZE-WITH-ATTR-NEXT: [[TMP11:%.*]] = tail call i64 @llvm.smax.i64(i64 [[TMP10]], i64 0)
// SANITIZE-WITH-ATTR-NEXT: [[DOTTR:%.*]] = trunc nuw i64 [[TMP11]] to i32
// SANITIZE-WITH-ATTR-NEXT: [[DOTTR:%.*]] = trunc nuw nsw i64 [[TMP11]] to i32
// SANITIZE-WITH-ATTR-NEXT: [[CONV54:%.*]] = shl i32 [[DOTTR]], 2
// SANITIZE-WITH-ATTR-NEXT: [[CONV55:%.*]] = and i32 [[CONV54]], 252
// SANITIZE-WITH-ATTR-NEXT: store i32 [[CONV55]], ptr [[ARRAYIDX65]], align 4, !tbaa [[TBAA4]]
31 changes: 31 additions & 0 deletions llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
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Original file line number Diff line number Diff line change
@@ -1212,6 +1212,34 @@ static bool processAnd(BinaryOperator *BinOp, LazyValueInfo *LVI) {
return true;
}

static bool processTrunc(TruncInst *TI, LazyValueInfo *LVI) {
if (TI->hasNoSignedWrap() && TI->hasNoUnsignedWrap())
return false;

ConstantRange Range =
LVI->getConstantRangeAtUse(TI->getOperandUse(0), /*UndefAllowed=*/false);
uint64_t DestWidth = TI->getDestTy()->getScalarSizeInBits();
bool Changed = false;

if (!TI->hasNoUnsignedWrap()) {
if (Range.getActiveBits() <= DestWidth) {
TI->setHasNoUnsignedWrap(true);
++NumNUW;
Changed = true;
}
}

if (!TI->hasNoSignedWrap()) {
if (Range.getMinSignedBits() <= DestWidth) {
TI->setHasNoSignedWrap(true);
++NumNSW;
Changed = true;
}
}

return Changed;
}

static bool runImpl(Function &F, LazyValueInfo *LVI, DominatorTree *DT,
const SimplifyQuery &SQ) {
bool FnChanged = false;
@@ -1275,6 +1303,9 @@ static bool runImpl(Function &F, LazyValueInfo *LVI, DominatorTree *DT,
case Instruction::And:
BBChanged |= processAnd(cast<BinaryOperator>(&II), LVI);
break;
case Instruction::Trunc:
BBChanged |= processTrunc(cast<TruncInst>(&II), LVI);
break;
}
}

2 changes: 1 addition & 1 deletion llvm/test/Transforms/CorrelatedValuePropagation/icmp.ll
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Original file line number Diff line number Diff line change
@@ -339,7 +339,7 @@ define i1 @test12(i32 %x) {
; CHECK-NEXT: [[ZEXT:%.*]] = zext i32 [[X:%.*]] to i64
; CHECK-NEXT: [[MUL:%.*]] = mul nuw nsw i64 [[ZEXT]], 7
; CHECK-NEXT: [[SHR:%.*]] = lshr i64 [[MUL]], 32
; CHECK-NEXT: [[TRUNC:%.*]] = trunc i64 [[SHR]] to i32
; CHECK-NEXT: [[TRUNC:%.*]] = trunc nuw nsw i64 [[SHR]] to i32
; CHECK-NEXT: ret i1 true
;
%zext = zext i32 %x to i64
4 changes: 2 additions & 2 deletions llvm/test/Transforms/CorrelatedValuePropagation/range.ll
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Original file line number Diff line number Diff line change
@@ -937,7 +937,7 @@ entry:
define i1 @ctlz_with_range_metadata(i16 %x) {
; CHECK-LABEL: @ctlz_with_range_metadata(
; CHECK-NEXT: [[CTLZ:%.*]] = call i16 @llvm.ctlz.i16(i16 [[X:%.*]], i1 false), !range [[RNG5:![0-9]+]]
; CHECK-NEXT: [[TRUNC:%.*]] = trunc i16 [[CTLZ]] to i8
; CHECK-NEXT: [[TRUNC:%.*]] = trunc nuw nsw i16 [[CTLZ]] to i8
; CHECK-NEXT: ret i1 true
;
%ctlz = call i16 @llvm.ctlz.i16(i16 %x, i1 false), !range !{i16 0, i16 8}
@@ -949,7 +949,7 @@ define i1 @ctlz_with_range_metadata(i16 %x) {
define i1 @abs_with_range_metadata(i16 %x) {
; CHECK-LABEL: @abs_with_range_metadata(
; CHECK-NEXT: [[ABS:%.*]] = call i16 @llvm.abs.i16(i16 [[X:%.*]], i1 false), !range [[RNG5]]
; CHECK-NEXT: [[TRUNC:%.*]] = trunc i16 [[ABS]] to i8
; CHECK-NEXT: [[TRUNC:%.*]] = trunc nuw nsw i16 [[ABS]] to i8
; CHECK-NEXT: ret i1 true
;
%abs = call i16 @llvm.abs.i16(i16 %x, i1 false), !range !{i16 0, i16 8}
8 changes: 4 additions & 4 deletions llvm/test/Transforms/CorrelatedValuePropagation/sext.ll
View file
Original file line number Diff line number Diff line change
@@ -20,7 +20,7 @@ define void @test1(i32 %n) {
; CHECK: for.body:
; CHECK-NEXT: [[EXT_WIDE1:%.*]] = zext nneg i32 [[A]] to i64
; CHECK-NEXT: call void @use64(i64 [[EXT_WIDE1]])
; CHECK-NEXT: [[EXT]] = trunc i64 [[EXT_WIDE1]] to i32
; CHECK-NEXT: [[EXT]] = trunc nuw nsw i64 [[EXT_WIDE1]] to i32
; CHECK-NEXT: br label [[FOR_COND]]
; CHECK: for.end:
; CHECK-NEXT: ret void
@@ -55,7 +55,7 @@ define void @test2(i32 %n) {
; CHECK: for.body:
; CHECK-NEXT: [[EXT_WIDE:%.*]] = sext i32 [[A]] to i64
; CHECK-NEXT: call void @use64(i64 [[EXT_WIDE]])
; CHECK-NEXT: [[EXT]] = trunc i64 [[EXT_WIDE]] to i32
; CHECK-NEXT: [[EXT]] = trunc nsw i64 [[EXT_WIDE]] to i32
; CHECK-NEXT: br label [[FOR_COND]]
; CHECK: for.end:
; CHECK-NEXT: ret void
@@ -87,7 +87,7 @@ define void @test3(i32 %n) {
; CHECK: bb:
; CHECK-NEXT: [[EXT_WIDE1:%.*]] = zext nneg i32 [[N]] to i64
; CHECK-NEXT: call void @use64(i64 [[EXT_WIDE1]])
; CHECK-NEXT: [[EXT:%.*]] = trunc i64 [[EXT_WIDE1]] to i32
; CHECK-NEXT: [[EXT:%.*]] = trunc nuw nsw i64 [[EXT_WIDE1]] to i32
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
@@ -115,7 +115,7 @@ define void @test4(i32 %n) {
; CHECK: bb:
; CHECK-NEXT: [[EXT_WIDE:%.*]] = sext i32 [[N]] to i64
; CHECK-NEXT: call void @use64(i64 [[EXT_WIDE]])
; CHECK-NEXT: [[EXT:%.*]] = trunc i64 [[EXT_WIDE]] to i32
; CHECK-NEXT: [[EXT:%.*]] = trunc nsw i64 [[EXT_WIDE]] to i32
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
108 changes: 108 additions & 0 deletions llvm/test/Transforms/CorrelatedValuePropagation/trunc.ll
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,108 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
; RUN: opt < %s -passes=correlated-propagation -S | FileCheck %s


define i1 @infer_nuw(i8 range(i8 0, 2) %A, i8 range(i8 0, 2) %B) {
; CHECK-LABEL: define i1 @infer_nuw(
; CHECK-SAME: i8 range(i8 0, 2) [[A:%.*]], i8 range(i8 0, 2) [[B:%.*]]) {
; CHECK-NEXT: [[XOR:%.*]] = xor i8 [[B]], [[A]]
; CHECK-NEXT: [[TRUNC:%.*]] = trunc nuw i8 [[XOR]] to i1
; CHECK-NEXT: ret i1 [[TRUNC]]
;
%xor = xor i8 %B, %A
%trunc = trunc i8 %xor to i1
ret i1 %trunc
}


define i4 @infer_nsw(i8 %A) {
; CHECK-LABEL: define range(i4 -4, 4) i4 @infer_nsw(
; CHECK-SAME: i8 [[A:%.*]]) {
; CHECK-NEXT: [[ASHR:%.*]] = ashr i8 [[A]], 5
; CHECK-NEXT: [[B:%.*]] = trunc nsw i8 [[ASHR]] to i4
; CHECK-NEXT: ret i4 [[B]]
;
%ashr = ashr i8 %A, 5
%result = trunc i8 %ashr to i4
ret i4 %result
}


define i8 @infer_nuw_nsw(i16 range(i16 -5, -3) %A, i16 range(i16 -5, -3) %B) {
; CHECK-LABEL: define range(i8 0, 8) i8 @infer_nuw_nsw(
; CHECK-SAME: i16 range(i16 -5, -3) [[A:%.*]], i16 range(i16 -5, -3) [[B:%.*]]) {
; CHECK-NEXT: [[XOR:%.*]] = xor i16 [[B]], [[A]]
; CHECK-NEXT: [[TRUNC:%.*]] = trunc nuw nsw i16 [[XOR]] to i8
; CHECK-NEXT: ret i8 [[TRUNC]]
;
%xor = xor i16 %B, %A
%trunc = trunc i16 %xor to i8
ret i8 %trunc
}


define i8 @infer_nsw_from_assume(i16 %x) {
; CHECK-LABEL: define i8 @infer_nsw_from_assume(
; CHECK-SAME: i16 [[X:%.*]]) {
; CHECK-NEXT: [[ADD:%.*]] = add i16 [[X]], 128
; CHECK-NEXT: [[OR_COND_I:%.*]] = icmp ult i16 [[ADD]], 256
; CHECK-NEXT: tail call void @llvm.assume(i1 [[OR_COND_I]])
; CHECK-NEXT: [[CONV1:%.*]] = trunc nsw i16 [[X]] to i8
; CHECK-NEXT: ret i8 [[CONV1]]
;
%add = add i16 %x, 128
%or.cond.i = icmp ult i16 %add, 256
tail call void @llvm.assume(i1 %or.cond.i)
%conv1 = trunc i16 %x to i8
ret i8 %conv1
}


define i1 @rust_issue_122734(i8 range(i8 0, 3) %A, i8 range(i8 0, 3) %B) {
; CHECK-LABEL: define i1 @rust_issue_122734(
; CHECK-SAME: i8 range(i8 0, 3) [[A:%.*]], i8 range(i8 0, 3) [[B:%.*]]) {
; CHECK-NEXT: [[START:.*]]:
; CHECK-NEXT: [[LHS:%.*]] = icmp eq i8 [[A]], 2
; CHECK-NEXT: [[RHS:%.*]] = icmp eq i8 [[B]], 2
; CHECK-NEXT: [[OR:%.*]] = or i1 [[LHS]], [[RHS]]
; CHECK-NEXT: [[AND:%.*]] = and i1 [[LHS]], [[RHS]]
; CHECK-NEXT: br i1 [[OR]], label %[[IFTRUE:.*]], label %[[IFFALSE:.*]]
; CHECK: [[IFTRUE]]:
; CHECK-NEXT: [[PHI:%.*]] = phi i1 [ [[XOR2:%.*]], %[[IFFALSE]] ], [ [[AND]], %[[START]] ]
; CHECK-NEXT: ret i1 [[PHI]]
; CHECK: [[IFFALSE]]:
; CHECK-NEXT: [[XOR:%.*]] = xor i8 [[A]], [[B]]
; CHECK-NEXT: [[TRUNC:%.*]] = trunc nuw i8 [[XOR]] to i1
; CHECK-NEXT: [[XOR2]] = xor i1 [[TRUNC]], true
; CHECK-NEXT: br label %[[IFTRUE]]
;
start:
%lhs = icmp eq i8 %A, 2
%rhs = icmp eq i8 %B, 2
%or = or i1 %lhs, %rhs
%and = and i1 %lhs, %rhs
br i1 %or, label %iftrue, label %iffalse

iftrue:
%phi = phi i1 [ %xor2, %iffalse], [ %and, %start ]
ret i1 %phi

iffalse:
%xor = xor i8 %A, %B
%trunc = trunc i8 %xor to i1
%xor2 = xor i1 %trunc, true
br label %iftrue
}


define i1 @overdefined_range_negative(i8 %A, i8 %B) {
; CHECK-LABEL: define i1 @overdefined_range_negative(
; CHECK-SAME: i8 [[A:%.*]], i8 [[B:%.*]]) {
; CHECK-NEXT: [[XOR:%.*]] = xor i8 [[A]], [[B]]
; CHECK-NEXT: [[TRUNC:%.*]] = trunc i8 [[XOR]] to i1
; CHECK-NEXT: ret i1 [[TRUNC]]
;
%xor = xor i8 %A, %B
%trunc = trunc i8 %xor to i1
ret i1 %trunc
}
8 changes: 4 additions & 4 deletions llvm/test/Transforms/CorrelatedValuePropagation/zext.ll
View file
Original file line number Diff line number Diff line change
@@ -14,7 +14,7 @@ define void @test1(i32 %n) {
; CHECK: for.body:
; CHECK-NEXT: [[EXT_WIDE:%.*]] = zext nneg i32 [[A]] to i64
; CHECK-NEXT: call void @use64(i64 [[EXT_WIDE]])
; CHECK-NEXT: [[EXT]] = trunc i64 [[EXT_WIDE]] to i32
; CHECK-NEXT: [[EXT]] = trunc nuw nsw i64 [[EXT_WIDE]] to i32
; CHECK-NEXT: br label [[FOR_COND]]
; CHECK: for.end:
; CHECK-NEXT: ret void
@@ -49,7 +49,7 @@ define void @test2(i32 %n) {
; CHECK: for.body:
; CHECK-NEXT: [[EXT_WIDE:%.*]] = zext i32 [[A]] to i64
; CHECK-NEXT: call void @use64(i64 [[EXT_WIDE]])
; CHECK-NEXT: [[EXT]] = trunc i64 [[EXT_WIDE]] to i32
; CHECK-NEXT: [[EXT]] = trunc nuw i64 [[EXT_WIDE]] to i32
; CHECK-NEXT: br label [[FOR_COND]]
; CHECK: for.end:
; CHECK-NEXT: ret void
@@ -81,7 +81,7 @@ define void @test3(i32 %n) {
; CHECK: bb:
; CHECK-NEXT: [[EXT_WIDE:%.*]] = zext nneg i32 [[N]] to i64
; CHECK-NEXT: call void @use64(i64 [[EXT_WIDE]])
; CHECK-NEXT: [[EXT:%.*]] = trunc i64 [[EXT_WIDE]] to i32
; CHECK-NEXT: [[EXT:%.*]] = trunc nuw nsw i64 [[EXT_WIDE]] to i32
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
@@ -109,7 +109,7 @@ define void @test4(i32 %n) {
; CHECK: bb:
; CHECK-NEXT: [[EXT_WIDE:%.*]] = zext i32 [[N]] to i64
; CHECK-NEXT: call void @use64(i64 [[EXT_WIDE]])
; CHECK-NEXT: [[EXT:%.*]] = trunc i64 [[EXT_WIDE]] to i32
; CHECK-NEXT: [[EXT:%.*]] = trunc nuw i64 [[EXT_WIDE]] to i32
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void