[llvm] 925a111 - [CVP] Convert `sitofp` -> `uitofp nneg` and add `nneg` flag to `uitofp`

[Noah Goldstein via llvm-commits]

Author: Noah Goldstein
Date: 2024-05-07T14:57:29-05:00
New Revision: 925a11128c903c8554921c2b5700caf191ae61d6

URL: https://github.com/llvm/llvm-project/commit/925a11128c903c8554921c2b5700caf191ae61d6
DIFF: https://github.com/llvm/llvm-project/commit/925a11128c903c8554921c2b5700caf191ae61d6.diff

LOG: [CVP] Convert `sitofp` -> `uitofp nneg` and add `nneg` flag to `uitofp`

Similiar to the `InstCombine` changes, just furthering the scope of
the canonicalization/`uitofp nneg` support

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
    llvm/test/Transforms/CorrelatedValuePropagation/sitofp.ll
    llvm/test/Transforms/CorrelatedValuePropagation/uitofp.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp b/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
index 715cdaff9727..50b5fdb56720 100644
--- a/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
+++ b/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
@@ -62,6 +62,7 @@ STATISTIC(NumAShrsConverted, "Number of ashr converted to lshr");
 STATISTIC(NumAShrsRemoved, "Number of ashr removed");
 STATISTIC(NumSRems,     "Number of srem converted to urem");
 STATISTIC(NumSExt,      "Number of sext converted to zext");
+STATISTIC(NumSIToFP,    "Number of sitofp converted to uitofp");
 STATISTIC(NumSICmps,    "Number of signed icmp preds simplified to unsigned");
 STATISTIC(NumAnd,       "Number of ands removed");
 STATISTIC(NumNW,        "Number of no-wrap deductions");
@@ -89,7 +90,7 @@ STATISTIC(NumSMinMax,
           "Number of llvm.s{min,max} intrinsics simplified to unsigned");
 STATISTIC(NumUDivURemsNarrowedExpanded,
           "Number of bound udiv's/urem's expanded");
-STATISTIC(NumZExt, "Number of non-negative deductions");
+STATISTIC(NumNNeg, "Number of zext/uitofp non-negative deductions");
 
 static Constant *getConstantAt(Value *V, Instruction *At, LazyValueInfo *LVI) {
   if (Constant *C = LVI->getConstant(V, At))
@@ -1075,20 +1076,49 @@ static bool processSExt(SExtInst *SDI, LazyValueInfo *LVI) {
   return true;
 }
 
-static bool processZExt(ZExtInst *ZExt, LazyValueInfo *LVI) {
-  if (ZExt->getType()->isVectorTy())
+static bool processPossibleNonNeg(PossiblyNonNegInst *I, LazyValueInfo *LVI) {
+  if (I->getType()->isVectorTy())
     return false;
 
-  if (ZExt->hasNonNeg())
+  if (I->hasNonNeg())
     return false;
 
-  const Use &Base = ZExt->getOperandUse(0);
+  const Use &Base = I->getOperandUse(0);
   if (!LVI->getConstantRangeAtUse(Base, /*UndefAllowed*/ false)
            .isAllNonNegative())
     return false;
 
-  ++NumZExt;
-  ZExt->setNonNeg();
+  ++NumNNeg;
+  I->setNonNeg();
+
+  return true;
+}
+
+static bool processZExt(ZExtInst *ZExt, LazyValueInfo *LVI) {
+  return processPossibleNonNeg(cast<PossiblyNonNegInst>(ZExt), LVI);
+}
+
+static bool processUIToFP(UIToFPInst *UIToFP, LazyValueInfo *LVI) {
+  return processPossibleNonNeg(cast<PossiblyNonNegInst>(UIToFP), LVI);
+}
+
+static bool processSIToFP(SIToFPInst *SIToFP, LazyValueInfo *LVI) {
+  if (SIToFP->getType()->isVectorTy())
+    return false;
+
+  const Use &Base = SIToFP->getOperandUse(0);
+  if (!LVI->getConstantRangeAtUse(Base, /*UndefAllowed*/ false)
+           .isAllNonNegative())
+    return false;
+
+  ++NumSIToFP;
+  auto *UIToFP = CastInst::Create(Instruction::UIToFP, Base, SIToFP->getType(),
+                                  "", SIToFP->getIterator());
+  UIToFP->takeName(SIToFP);
+  UIToFP->setDebugLoc(SIToFP->getDebugLoc());
+  UIToFP->setNonNeg();
+  SIToFP->replaceAllUsesWith(UIToFP);
+  SIToFP->eraseFromParent();
 
   return true;
 }
@@ -1197,6 +1227,12 @@ static bool runImpl(Function &F, LazyValueInfo *LVI, DominatorTree *DT,
       case Instruction::ZExt:
         BBChanged |= processZExt(cast<ZExtInst>(&II), LVI);
         break;
+      case Instruction::UIToFP:
+        BBChanged |= processUIToFP(cast<UIToFPInst>(&II), LVI);
+        break;
+      case Instruction::SIToFP:
+        BBChanged |= processSIToFP(cast<SIToFPInst>(&II), LVI);
+        break;
       case Instruction::Add:
       case Instruction::Sub:
       case Instruction::Mul:

diff  --git a/llvm/test/Transforms/CorrelatedValuePropagation/sitofp.ll b/llvm/test/Transforms/CorrelatedValuePropagation/sitofp.ll
index 4bc649245d52..83533290e2f6 100644
--- a/llvm/test/Transforms/CorrelatedValuePropagation/sitofp.ll
+++ b/llvm/test/Transforms/CorrelatedValuePropagation/sitofp.ll
@@ -9,7 +9,7 @@ define void @test1(i32 %n) {
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[N:%.*]], -1
 ; CHECK-NEXT:    br i1 [[CMP]], label [[BB:%.*]], label [[EXIT:%.*]]
 ; CHECK:       bb:
-; CHECK-NEXT:    [[EXT_WIDE:%.*]] = sitofp i32 [[N]] to float
+; CHECK-NEXT:    [[EXT_WIDE:%.*]] = uitofp nneg i32 [[N]] to float
 ; CHECK-NEXT:    call void @use.f32(float [[EXT_WIDE]])
 ; CHECK-NEXT:    br label [[EXIT]]
 ; CHECK:       exit:
@@ -88,7 +88,7 @@ exit:
 define double @test_infer_at_use(i32 noundef %n) {
 ; CHECK-LABEL: @test_infer_at_use(
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[N:%.*]], -1
-; CHECK-NEXT:    [[EXT:%.*]] = sitofp i32 [[N]] to double
+; CHECK-NEXT:    [[EXT:%.*]] = uitofp nneg i32 [[N]] to double
 ; CHECK-NEXT:    [[SELECT:%.*]] = select i1 [[CMP]], double [[EXT]], double 0.000000e+00
 ; CHECK-NEXT:    ret double [[SELECT]]
 ;

diff  --git a/llvm/test/Transforms/CorrelatedValuePropagation/uitofp.ll b/llvm/test/Transforms/CorrelatedValuePropagation/uitofp.ll
index 0558ec61e636..32d0f5b4d338 100644
--- a/llvm/test/Transforms/CorrelatedValuePropagation/uitofp.ll
+++ b/llvm/test/Transforms/CorrelatedValuePropagation/uitofp.ll
@@ -9,7 +9,7 @@ define void @test1(i32 %n) {
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[N:%.*]], -1
 ; CHECK-NEXT:    br i1 [[CMP]], label [[BB:%.*]], label [[EXIT:%.*]]
 ; CHECK:       bb:
-; CHECK-NEXT:    [[EXT_WIDE:%.*]] = uitofp i32 [[N]] to float
+; CHECK-NEXT:    [[EXT_WIDE:%.*]] = uitofp nneg i32 [[N]] to float
 ; CHECK-NEXT:    call void @use.f32(float [[EXT_WIDE]])
 ; CHECK-NEXT:    br label [[EXIT]]
 ; CHECK:       exit:
@@ -87,7 +87,7 @@ exit:
 define double @test_infer_at_use(i32 noundef %n) {
 ; CHECK-LABEL: @test_infer_at_use(
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[N:%.*]], -1
-; CHECK-NEXT:    [[EXT:%.*]] = uitofp i32 [[N]] to double
+; CHECK-NEXT:    [[EXT:%.*]] = uitofp nneg i32 [[N]] to double
 ; CHECK-NEXT:    [[SELECT:%.*]] = select i1 [[CMP]], double [[EXT]], double 0.000000e+00
 ; CHECK-NEXT:    ret double [[SELECT]]
 ;