[llvm-commits] [llvm] r137836 - in /llvm/trunk: lib/Transforms/Scalar/SCCP.cpp test/Transforms/SCCP/undef-resolve.ll

[Eli Friedman]

Author: efriedma
Date: Wed Aug 17 13:10:43 2011
New Revision: 137836

URL: http://llvm.org/viewvc/llvm-project?rev=137836&view=rev
Log:
Silly mistake from r137777; restore significant isStructTy() checks.  While here, be a bit more defensive
with unknown instructions.

Fixes PR10687.


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=137836&r1=137835&r2=137836&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SCCP.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SCCP.cpp Wed Aug 17 13:10:43 2011
@@ -1436,7 +1436,7 @@
         // Only a few things that can be structs matter for undef.  Just send
         // all their results to overdefined.  We could be more precise than this
         // but it isn't worth bothering.
-        if (isa<CallInst>(I) || isa<SelectInst>(I)) {
+        if (!isa<ExtractValueInst>(I) && !isa<InsertValueInst>(I)) {
           for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
             LatticeVal &LV = getStructValueState(I, i);
             if (LV.isUndefined())
@@ -1449,16 +1449,31 @@
       LatticeVal &LV = getValueState(I);
       if (!LV.isUndefined()) continue;
 
+      // extractvalue is safe; check here because the argument is a struct.
+      if (isa<ExtractValueInst>(I))
+        continue;
+
+      // Compute the operand LatticeVals, for convenience below.
+      // Anything taking a struct is conservatively assumed to require
+      // overdefined markings.
+      if (I->getOperand(0)->getType()->isStructTy()) {
+        markOverdefined(I);
+        return true;
+      }
       LatticeVal Op0LV = getValueState(I->getOperand(0));
       LatticeVal Op1LV;
-      if (I->getNumOperands() == 2)
+      if (I->getNumOperands() == 2) {
+        if (I->getOperand(1)->getType()->isStructTy()) {
+          markOverdefined(I);
+          return true;
+        }
+
         Op1LV = getValueState(I->getOperand(1));
+      }
       // If this is an instructions whose result is defined even if the input is
       // not fully defined, propagate the information.
       Type *ITy = I->getType();
       switch (I->getOpcode()) {
-      case Instruction::ExtractValue:
-        break; // Extract of undef -> undef
       case Instruction::Add:
       case Instruction::Sub:
       case Instruction::Trunc:

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=137836&r1=137835&r2=137836&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SCCP/undef-resolve.ll (original)
+++ llvm/trunk/test/Transforms/SCCP/undef-resolve.ll Wed Aug 17 13:10:43 2011
@@ -161,3 +161,12 @@
 ; CHECK: @test9
 ; CHECK: icmp ugt
 }
+
+; Make sure we handle extractvalue
+define i64 @test10() { 
+entry:
+  %e = extractvalue { i64, i64 } undef, 1
+  ret i64 %e
+; CHECK: @test10
+; CHECK: ret i64 undef
+}