[llvm-commits] [llvm] r166049 - in /llvm/trunk: lib/CodeGen/SelectionDAG/DAGCombiner.cpp test/CodeGen/X86/trunc-fp2int.ll
Michael Liao
michael.liao at intel.com
Tue Oct 16 12:38:36 PDT 2012
Author: hliao
Date: Tue Oct 16 14:38:35 2012
New Revision: 166049
URL: http://llvm.org/viewvc/llvm-project?rev=166049&view=rev
Log:
Teach DAG combine to fold (trunc (fptoXi x)) to (fptoXi x)
Added:
llvm/trunk/test/CodeGen/X86/trunc-fp2int.ll
Modified:
llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=166049&r1=166048&r2=166049&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Tue Oct 16 14:38:35 2012
@@ -5308,6 +5308,52 @@
if (Reduced.getNode())
return Reduced;
}
+ // fold (trunc (fptoXi x)) -> (smaller fptoXi x)
+ if ((N0.getOpcode() == ISD::FP_TO_UINT ||
+ N0.getOpcode() == ISD::FP_TO_SINT) && !LegalTypes)
+ return DAG.getNode(N0.getOpcode(), N->getDebugLoc(), VT, N0.getOperand(0));
+ // fold (trunc (concat ... x ...)) -> (concat ..., (trunc x), ...)),
+ // where ... are all 'undef'.
+ if (N0.getOpcode() == ISD::CONCAT_VECTORS && !LegalTypes) {
+ SmallVector<EVT, 8> VTs;
+ SDValue V;
+ unsigned Idx = 0;
+ unsigned NumDefs = 0;
+
+ for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i) {
+ SDValue X = N0.getOperand(i);
+ if (X.getOpcode() != ISD::UNDEF) {
+ V = X;
+ Idx = i;
+ NumDefs++;
+ }
+ // Stop if more than one members are non-undef.
+ if (NumDefs > 1)
+ break;
+ VTs.push_back(EVT::getVectorVT(*DAG.getContext(),
+ VT.getVectorElementType(),
+ X.getValueType().getVectorNumElements()));
+ }
+
+ if (NumDefs == 0)
+ return DAG.getUNDEF(VT);
+
+ if (NumDefs == 1) {
+ assert(V.getNode() && "The single defined operand is empty!");
+ SmallVector<SDValue, 8> Opnds;
+ for (unsigned i = 0, e = VTs.size(); i != e; ++i) {
+ if (i != Idx) {
+ Opnds.push_back(DAG.getUNDEF(VTs[i]));
+ continue;
+ }
+ SDValue NV = DAG.getNode(ISD::TRUNCATE, V.getDebugLoc(), VTs[i], V);
+ AddToWorkList(NV.getNode());
+ Opnds.push_back(NV);
+ }
+ return DAG.getNode(ISD::CONCAT_VECTORS, N->getDebugLoc(), VT,
+ &Opnds[0], Opnds.size());
+ }
+ }
// Simplify the operands using demanded-bits information.
if (!VT.isVector() &&
Added: llvm/trunk/test/CodeGen/X86/trunc-fp2int.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/trunc-fp2int.ll?rev=166049&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/trunc-fp2int.ll (added)
+++ llvm/trunk/test/CodeGen/X86/trunc-fp2int.ll Tue Oct 16 14:38:35 2012
@@ -0,0 +1,18 @@
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mcpu=corei7 | FileCheck %s
+
+define <4 x i8> @bar(<4 x float> %in) nounwind readnone alwaysinline {
+ %1 = fptoui <4 x float> %in to <4 x i8>
+ ret <4 x i8> %1
+; CHECK: bar
+; CHECK: cvttps2dq
+}
+define <4 x i8> @foo(<4 x float> %in) nounwind readnone alwaysinline {
+ %1 = fptoui <4 x float> %in to <4 x i32>
+ %2 = trunc <4 x i32> %1 to <4 x i16>
+ %3 = shufflevector <4 x i16> %2, <4 x i16> undef, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+ %4 = trunc <8 x i16> %3 to <8 x i8>
+ %5 = shufflevector <8 x i8> %4, <8 x i8> undef, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+ ret <4 x i8> %5
+; CHECK: foo
+; CHECK: cvttps2dq
+}
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