Re: [llvm-commits] CVS: llvm/lib/Transforms/Scalar/IndVarSimplify.cpp

[Sheng Zhou]

Chris,

Attached is the testcase, which will get:





Sheng



  DOUT << "INDVARS: New CanIV: " << *IndVar;

opt: /developer/home2/zsth/llvm-gcc-dev/HEAD/llvm/llvm/lib/VMCore/Constants.cpp:1559: static llvm::Constant* llvm::ConstantExpr::getZExt(llvm::Constant*, const llvm::Type*): Assertion `C->getType()->getPrimitiveSizeInBits() < Ty->getPrimitiveSizeInBits()&& "SrcTy must be smaller than DestTy for ZExt!"' failed. The condition "IterationCount->getType() != LargestType" doesn't mean the IterationCount->getType's bitwidth < LargestType's so, sometimes, (like in this testcase), it need a trunc not ext. This patch is to fix it.

   if (!isa<SCEVCouldNotCompute>(IterationCount)) {
-    if (IterationCount->getType() != LargestType)
+    if (IterationCount->getType()->getPrimitiveSizeInBits() <
+        LargestType->getPrimitiveSizeInBits())

+    else if (IterationCount->getType() != LargestType)

       DeadInsts.insert(DI);
   }

IterationCount = SCEVZeroExtendExpr::get(IterationCount, LargestType); + IterationCount = SCEVTruncateExpr::get(IterationCount, LargestType); if (Instruction *DI = LinearFunctionTestReplace(L, IterationCount,Rewriter))

testcase.bc
Description: Binary data

; ModuleID = 'testcase.bc'
target datalayout = 
"e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64"
target triple = "i686-pc-linux-gnu"

define i32 @testcase(i5 zext  %k) {
entry:
        br label %bb2

bb:             ; preds = %bb2
        %tmp1 = add i32 %tmp2, %result          ; <i32> [#uses=1]
        %indvar_next1 = add i5 %k_0, 1          ; <i5> [#uses=1]
        br label %bb2

bb2:            ; preds = %bb, %entry
        %k_0 = phi i5 [ 0, %entry ], [ %indvar_next1, %bb ]             ; <i5> 
[#uses=2]
        %result = phi i32 [ 0, %entry ], [ %tmp1, %bb ]         ; <i32> 
[#uses=2]
        %tmp2 = zext i5 %k_0 to i32             ; <i32> [#uses=1]
        %exitcond = icmp eq i32 %tmp2, 16               ; <i1> [#uses=1]
        br i1 %exitcond, label %bb3, label %bb

bb3:            ; preds = %bb2
        ret i32 %result
}

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