From fbd62fe60fb2281ca33da35dc25ca3c87ec0bb51 Mon Sep 17 00:00:00 2001
From: Cullen Rhodes <cullen.rhodes@arm.com>
Date: Tue, 13 Oct 2020 12:26:47 +0000
Subject: [PATCH] [ValueTracking] Clarify TypeSize comparisons

TypeSize comparisons using overloaded operators should be replaced by
the new isKnownXY comparators when the operands can be fixed-length or
scalable vectors.

In ValueTracking there are several uses of the overloaded operators in
`isKnownNonZero` and `ComputeMultiple`. In the former we already bail
out on scalable vectors since we currently have no way to represent
DemandedElts, and the latter is operating on scalar integers, so we can
assume fixed-size in both instances.

Reviewed By: david-arm

Differential Revision: https://reviews.llvm.org/D89387
---
 llvm/lib/Analysis/ValueTracking.cpp | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index c6672fc..c44ad00 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -2256,8 +2256,9 @@ bool isKnownNonZero(const Value *V, const APInt &DemandedElts, unsigned Depth,
       // See the comment for IntToPtr/PtrToInt instructions below.
       if (CE->getOpcode() == Instruction::IntToPtr ||
           CE->getOpcode() == Instruction::PtrToInt)
-        if (Q.DL.getTypeSizeInBits(CE->getOperand(0)->getType()) <=
-            Q.DL.getTypeSizeInBits(CE->getType()))
+        if (Q.DL.getTypeSizeInBits(CE->getOperand(0)->getType())
+                .getFixedSize() <=
+            Q.DL.getTypeSizeInBits(CE->getType()).getFixedSize())
           return isKnownNonZero(CE->getOperand(0), Depth, Q);
     }
 
@@ -2354,16 +2355,16 @@ bool isKnownNonZero(const Value *V, const APInt &DemandedElts, unsigned Depth,
       return isKnownNonZero(BCO->getOperand(0), Depth, Q);
 
     if (auto *I2P = dyn_cast<IntToPtrInst>(V))
-      if (Q.DL.getTypeSizeInBits(I2P->getSrcTy()) <=
-          Q.DL.getTypeSizeInBits(I2P->getDestTy()))
+      if (Q.DL.getTypeSizeInBits(I2P->getSrcTy()).getFixedSize() <=
+          Q.DL.getTypeSizeInBits(I2P->getDestTy()).getFixedSize())
         return isKnownNonZero(I2P->getOperand(0), Depth, Q);
   }
 
   // Similar to int2ptr above, we can look through ptr2int here if the cast
   // is a no-op or an extend and not a truncate.
   if (auto *P2I = dyn_cast<PtrToIntInst>(V))
-    if (Q.DL.getTypeSizeInBits(P2I->getSrcTy()) <=
-        Q.DL.getTypeSizeInBits(P2I->getDestTy()))
+    if (Q.DL.getTypeSizeInBits(P2I->getSrcTy()).getFixedSize() <=
+        Q.DL.getTypeSizeInBits(P2I->getDestTy()).getFixedSize())
       return isKnownNonZero(P2I->getOperand(0), Depth, Q);
 
   unsigned BitWidth = getBitWidth(V->getType()->getScalarType(), Q.DL);
@@ -3059,11 +3060,11 @@ bool llvm::ComputeMultiple(Value *V, unsigned Base, Value *&Multiple,
     if (ComputeMultiple(Op0, Base, Mul0, LookThroughSExt, Depth+1)) {
       if (Constant *Op1C = dyn_cast<Constant>(Op1))
         if (Constant *MulC = dyn_cast<Constant>(Mul0)) {
-          if (Op1C->getType()->getPrimitiveSizeInBits() <
-              MulC->getType()->getPrimitiveSizeInBits())
+          if (Op1C->getType()->getPrimitiveSizeInBits().getFixedSize() <
+              MulC->getType()->getPrimitiveSizeInBits().getFixedSize())
             Op1C = ConstantExpr::getZExt(Op1C, MulC->getType());
-          if (Op1C->getType()->getPrimitiveSizeInBits() >
-              MulC->getType()->getPrimitiveSizeInBits())
+          if (Op1C->getType()->getPrimitiveSizeInBits().getFixedSize() >
+              MulC->getType()->getPrimitiveSizeInBits().getFixedSize())
             MulC = ConstantExpr::getZExt(MulC, Op1C->getType());
 
           // V == Base * (Mul0 * Op1), so return (Mul0 * Op1)
@@ -3083,11 +3084,11 @@ bool llvm::ComputeMultiple(Value *V, unsigned Base, Value *&Multiple,
     if (ComputeMultiple(Op1, Base, Mul1, LookThroughSExt, Depth+1)) {
       if (Constant *Op0C = dyn_cast<Constant>(Op0))
         if (Constant *MulC = dyn_cast<Constant>(Mul1)) {
-          if (Op0C->getType()->getPrimitiveSizeInBits() <
-              MulC->getType()->getPrimitiveSizeInBits())
+          if (Op0C->getType()->getPrimitiveSizeInBits().getFixedSize() <
+              MulC->getType()->getPrimitiveSizeInBits().getFixedSize())
             Op0C = ConstantExpr::getZExt(Op0C, MulC->getType());
-          if (Op0C->getType()->getPrimitiveSizeInBits() >
-              MulC->getType()->getPrimitiveSizeInBits())
+          if (Op0C->getType()->getPrimitiveSizeInBits().getFixedSize() >
+              MulC->getType()->getPrimitiveSizeInBits().getFixedSize())
             MulC = ConstantExpr::getZExt(MulC, Op0C->getType());
 
           // V == Base * (Mul1 * Op0), so return (Mul1 * Op0)
-- 
2.7.4