[llvm-commits] [polly] r152913 - in /polly/trunk: lib/Support/SCEVValidator.cpp test/ScopInfo/2012-03-16-Crash-because-of-unsigned-in-scev.ll

[Sebastian Pop]

Hi Tobi,

it looks like this change breaks in code generation with:
"Use still stuck around after Def is destroyed"

   class ValidatorResult visitSMaxExpr(const SCEVSMaxExpr *Expr) {
-    ValidatorResult Return(SCEVType::INT);
+    ValidatorResult Return(SCEVType::INT, Expr);

    for (int i = 0, e = Expr->getNumOperands(); i < e; ++i) {
      ValidatorResult Op = visit(Expr->getOperand(i));

      if (!Op.isValid())
        return Op;

      Return.merge(Op);
    }

    return Return;
  }

The problem seems to be that we are adding the full original
SMax expression to the result
and that references SSA names of the original scop.

Ok to revert this change?


On Fri, Mar 16, 2012 at 5:16 AM, Tobias Grosser
<grosser at fim.uni-passau.de> wrote:
> Author: grosser
> Date: Fri Mar 16 05:16:28 2012
> New Revision: 152913
>
> URL: http://llvm.org/viewvc/llvm-project?rev=152913&view=rev
> Log:
> SCEVValidator: Ensure that parameters are recorded correctly
>
> This also fixes UMax where we did not correctly keep track of the parameters.
> Fixes PR12275.
>
> Reported-By: Sebastian Pop  <sebpop at gmail.com>
>
> Added:
>     polly/trunk/test/ScopInfo/2012-03-16-Crash-because-of-unsigned-in-scev.ll
> Modified:
>     polly/trunk/lib/Support/SCEVValidator.cpp
>
> Modified: polly/trunk/lib/Support/SCEVValidator.cpp
> URL: http://llvm.org/viewvc/llvm-project/polly/trunk/lib/Support/SCEVValidator.cpp?rev=152913&r1=152912&r2=152913&view=diff
> ==============================================================================
> --- polly/trunk/lib/Support/SCEVValidator.cpp (original)
> +++ polly/trunk/lib/Support/SCEVValidator.cpp Fri Mar 16 05:16:28 2012
> @@ -52,7 +52,9 @@
>    };
>
>    /// @brief Construct a result with a certain type and no parameters.
> -  ValidatorResult(SCEVType::TYPE Type) : Type(Type) {};
> +  ValidatorResult(SCEVType::TYPE Type) : Type(Type) {
> +    assert(Type != SCEVType::PARAM && "Did you forget to pass the parameter");
> +  };
>
>    /// @brief Construct a result with a certain type and a single parameter.
>    ValidatorResult(SCEVType::TYPE Type, const SCEV *Expr) : Type(Type) {
> @@ -247,7 +249,7 @@
>    }
>
>    class ValidatorResult visitSMaxExpr(const SCEVSMaxExpr *Expr) {
> -    ValidatorResult Return(SCEVType::INT);
> +    ValidatorResult Return(SCEVType::INT, Expr);
>
>      for (int i = 0, e = Expr->getNumOperands(); i < e; ++i) {
>        ValidatorResult Op = visit(Expr->getOperand(i));
> @@ -262,8 +264,6 @@
>    }
>
>    class ValidatorResult visitUMaxExpr(const SCEVUMaxExpr *Expr) {
> -    ValidatorResult Return(SCEVType::PARAM);
> -
>      // We do not support unsigned operations. If 'Expr' is constant during Scop
>      // execution we treat this as a parameter, otherwise we bail out.
>      for (int i = 0, e = Expr->getNumOperands(); i < e; ++i) {
> @@ -271,11 +271,9 @@
>
>        if (!Op.isConstant())
>          return ValidatorResult(SCEVType::INVALID);
> -
> -      Return.merge(Op);
>      }
>
> -    return Return;
> +    return ValidatorResult(SCEVType::PARAM, Expr);
>    }
>
>    ValidatorResult visitUnknown(const SCEVUnknown *Expr) {
>
> Added: polly/trunk/test/ScopInfo/2012-03-16-Crash-because-of-unsigned-in-scev.ll
> URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/ScopInfo/2012-03-16-Crash-because-of-unsigned-in-scev.ll?rev=152913&view=auto
> ==============================================================================
> --- polly/trunk/test/ScopInfo/2012-03-16-Crash-because-of-unsigned-in-scev.ll (added)
> +++ polly/trunk/test/ScopInfo/2012-03-16-Crash-because-of-unsigned-in-scev.ll Fri Mar 16 05:16:28 2012
> @@ -0,0 +1,32 @@
> +; RUN: opt %loadPolly -polly-scops -analyze < %s | FileCheck %s
> +
> +target datalayout = "e-p:32:32:32-i64:64:64-i32:32:32-i16:16:16-i1:32:32f64:64:64-f32:32:32-a0:0-n32"
> +target triple = "hexagon-unknown-linux-gnu"
> +
> + at array = external global [64 x i8], align 8
> +
> +define void @foo(i32* %A) nounwind {
> +entry:
> +  br label %if.then132
> +
> +if.then132:
> +  %loaded = load i32* %A
> +  %0 = icmp ugt i32 %loaded, 10
> +  %umax = select i1 %0, i32 %loaded, i32 10
> +  br label %do.body
> +
> +do.body:
> +  %indvar = phi i32 [ %3, %do.body ], [ 0, %if.then132 ]
> +  %1 = add i32 0, %umax
> +  %2 = sub i32 %1, %indvar
> +  %arrayidx = getelementptr [64 x i8]* @array, i32 0, i32 %2
> +  store i8 1, i8* %arrayidx, align 1
> +  %3 = add i32 %indvar, 1
> +  %exitcond = icmp eq i32 %3, 20
> +  br i1 %exitcond, label %for.end, label %do.body
> +
> +for.end:
> +  ret void
> +}
> +
> +;CHECK: p0: (10 umax %loaded)
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits



-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation