[llvm-commits] [llvm] r51535 - in /llvm/trunk: lib/Transforms/Scalar/SCCP.cpp test/Transforms/SCCP/2008-05-23-UndefCallFold.ll

[Chris Lattner]

Author: lattner
Date: Fri May 23 22:59:33 2008
New Revision: 51535

URL: http://llvm.org/viewvc/llvm-project?rev=51535&view=rev
Log:
Fix PR2358 by resolving calls with undef arguments to overdefined.


Added:
    llvm/trunk/test/Transforms/SCCP/2008-05-23-UndefCallFold.ll
Modified:
    llvm/trunk/lib/Transforms/Scalar/SCCP.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/SCCP.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SCCP.cpp?rev=51535&r1=51534&r2=51535&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SCCP.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SCCP.cpp Fri May 23 22:59:33 2008
@@ -1370,6 +1370,12 @@
         else
           markOverdefined(LV, I);
         return true;
+      case Instruction::Call:
+        // If a call has an undef result, it is because it is constant foldable
+        // but one of the inputs was undef.  Just force the result to
+        // overdefined.
+        markOverdefined(LV, I);
+        return true;
       }
     }
   

Added: llvm/trunk/test/Transforms/SCCP/2008-05-23-UndefCallFold.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SCCP/2008-05-23-UndefCallFold.ll?rev=51535&view=auto

==============================================================================
--- llvm/trunk/test/Transforms/SCCP/2008-05-23-UndefCallFold.ll (added)
+++ llvm/trunk/test/Transforms/SCCP/2008-05-23-UndefCallFold.ll Fri May 23 22:59:33 2008
@@ -0,0 +1,14 @@
+; RUN: llvm-as < %s | opt -sccp | llvm-dis | not grep {ret i32 undef}
+; PR2358
+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-f80:128:128"
+target triple = "i686-pc-linux-gnu"
+
+define i32 @x(i32 %b) {
+entry:
+ %val = call i32 @llvm.cttz.i32(i32 undef)
+ ret i32 %val
+}
+
+declare i32 @llvm.cttz.i32(i32)
+