[llvm-commits] [llvm] r102358 - in /llvm/trunk: lib/Transforms/Scalar/SCCP.cpp test/Transforms/SCCP/undef-resolve.ll

[Chris Lattner]

Author: lattner
Date: Mon Apr 26 13:21:23 2010
New Revision: 102358

URL: http://llvm.org/viewvc/llvm-project?rev=102358&view=rev
Log:
fix PR6940: sitofp(undef) folds to 0.0, not undef.

Modified:
    llvm/trunk/lib/Transforms/Scalar/SCCP.cpp
    llvm/trunk/test/Transforms/SCCP/undef-resolve.ll

Modified: llvm/trunk/lib/Transforms/Scalar/SCCP.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SCCP.cpp?rev=102358&r1=102357&r2=102358&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SCCP.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SCCP.cpp Mon Apr 26 13:21:23 2010
@@ -1452,6 +1452,8 @@
         // After a zero extend, we know the top part is zero.  SExt doesn't have
         // to be handled here, because we don't know whether the top part is 1's
         // or 0's.
+      case Instruction::SIToFP:  // some FP values are not possible, just use 0.
+      case Instruction::UIToFP:  // some FP values are not possible, just use 0.
         markForcedConstant(I, Constant::getNullValue(ITy));
         return true;
       case Instruction::Mul:

Modified: llvm/trunk/test/Transforms/SCCP/undef-resolve.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SCCP/undef-resolve.ll?rev=102358&r1=102357&r2=102358&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SCCP/undef-resolve.ll (original)
+++ llvm/trunk/test/Transforms/SCCP/undef-resolve.ll Mon Apr 26 13:21:23 2010
@@ -1,8 +1,19 @@
 ; RUN: opt %s -sccp -S | FileCheck %s
+
+
+; PR6940
+define double @test1() {
+  %t = sitofp i32 undef to double
+  ret double %t
+; CHECK: @test1
+; CHECK: ret double 0.0
+}
+
+
 ; rdar://7832370
 ; Check that lots of stuff doesn't get turned into undef.
-
-define i32 @main() nounwind readnone ssp {
+define i32 @test2() nounwind readnone ssp {
+; CHECK: @test2
 init:
   br label %control.outer.outer