diff options
| -rw-r--r-- | lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 2 | ||||
| -rw-r--r-- | test/CodeGen/X86/fold-sext-trunc.ll | 20 |
2 files changed, 21 insertions, 1 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index b937eaf..bd4b10e 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -2962,7 +2962,7 @@ SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) { if (NarrowLoad.getNode()) { if (NarrowLoad.getNode() != N0.getNode()) CombineTo(N0.getNode(), NarrowLoad); - return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, NarrowLoad); + return SDValue(N, 0); // Return N so it doesn't get rechecked! } // See if the value being truncated is already sign extended. If so, just diff --git a/test/CodeGen/X86/fold-sext-trunc.ll b/test/CodeGen/X86/fold-sext-trunc.ll new file mode 100644 index 0000000..1016b10 --- /dev/null +++ b/test/CodeGen/X86/fold-sext-trunc.ll @@ -0,0 +1,20 @@ +; RUN: llvm-as < %s | llc -march=x86-64 | grep movslq | count 1 +; PR4050 + + type { i64 } ; type %0 + %struct.S1 = type { i16, i32 } +@g_10 = external global %struct.S1 ; <%struct.S1*> [#uses=2] + +declare void @func_28(i64, i64) + +define void @int322(i32 %foo) nounwind { +entry: + %val = load i64* getelementptr (%0* bitcast (%struct.S1* @g_10 to %0*), i32 0, i32 0) ; <i64> [#uses=1] + %0 = load i32* getelementptr (%struct.S1* @g_10, i32 0, i32 1), align 4 ; <i32> [#uses=1] + %1 = sext i32 %0 to i64 ; <i64> [#uses=1] + %tmp4.i = lshr i64 %val, 32 ; <i64> [#uses=1] + %tmp5.i = trunc i64 %tmp4.i to i32 ; <i32> [#uses=1] + %2 = sext i32 %tmp5.i to i64 ; <i64> [#uses=1] + tail call void @func_28(i64 %2, i64 %1) nounwind + ret void +} |