[llvm-commits] [llvm] r161807 - in /llvm/trunk: include/llvm/ADT/APFloat.h lib/CodeGen/SelectionDAG/DAGCombiner.cpp lib/CodeGen/SelectionDAG/SelectionDAG.cpp lib/Support/APFloat.cpp test/CodeGen/ARM/floorf.ll
Owen Anderson
resistor at mac.com
Mon Aug 13 16:32:49 PDT 2012
Author: resistor
Date: Mon Aug 13 18:32:49 2012
New Revision: 161807
URL: http://llvm.org/viewvc/llvm-project?rev=161807&view=rev
Log:
Add a roundToIntegral method to APFloat, which can be parameterized over various rounding modes. Use this to implement SelectionDAG constant folding of FFLOOR, FCEIL, and FTRUNC.
Added:
llvm/trunk/test/CodeGen/ARM/floorf.ll
Modified:
llvm/trunk/include/llvm/ADT/APFloat.h
llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
llvm/trunk/lib/Support/APFloat.cpp
Modified: llvm/trunk/include/llvm/ADT/APFloat.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/APFloat.h?rev=161807&r1=161806&r2=161807&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/APFloat.h (original)
+++ llvm/trunk/include/llvm/ADT/APFloat.h Mon Aug 13 18:32:49 2012
@@ -274,6 +274,7 @@
/* C fmod, or llvm frem. */
opStatus mod(const APFloat &, roundingMode);
opStatus fusedMultiplyAdd(const APFloat &, const APFloat &, roundingMode);
+ opStatus roundToIntegral(roundingMode);
/* Sign operations. */
void changeSign();
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=161807&r1=161806&r2=161807&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Mon Aug 13 18:32:49 2012
@@ -228,6 +228,9 @@
SDValue visitFP_EXTEND(SDNode *N);
SDValue visitFNEG(SDNode *N);
SDValue visitFABS(SDNode *N);
+ SDValue visitFCEIL(SDNode *N);
+ SDValue visitFTRUNC(SDNode *N);
+ SDValue visitFFLOOR(SDNode *N);
SDValue visitBRCOND(SDNode *N);
SDValue visitBR_CC(SDNode *N);
SDValue visitLOAD(SDNode *N);
@@ -1140,6 +1143,9 @@
case ISD::FP_EXTEND: return visitFP_EXTEND(N);
case ISD::FNEG: return visitFNEG(N);
case ISD::FABS: return visitFABS(N);
+ case ISD::FFLOOR: return visitFFLOOR(N);
+ case ISD::FCEIL: return visitFCEIL(N);
+ case ISD::FTRUNC: return visitFTRUNC(N);
case ISD::BRCOND: return visitBRCOND(N);
case ISD::BR_CC: return visitBR_CC(N);
case ISD::LOAD: return visitLOAD(N);
@@ -6243,6 +6249,42 @@
return SDValue();
}
+SDValue DAGCombiner::visitFCEIL(SDNode *N) {
+ SDValue N0 = N->getOperand(0);
+ ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
+ EVT VT = N->getValueType(0);
+
+ // fold (fceil c1) -> fceil(c1)
+ if (N0CFP && VT != MVT::ppcf128)
+ return DAG.getNode(ISD::FCEIL, N->getDebugLoc(), VT, N0);
+
+ return SDValue();
+}
+
+SDValue DAGCombiner::visitFTRUNC(SDNode *N) {
+ SDValue N0 = N->getOperand(0);
+ ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
+ EVT VT = N->getValueType(0);
+
+ // fold (ftrunc c1) -> ftrunc(c1)
+ if (N0CFP && VT != MVT::ppcf128)
+ return DAG.getNode(ISD::FTRUNC, N->getDebugLoc(), VT, N0);
+
+ return SDValue();
+}
+
+SDValue DAGCombiner::visitFFLOOR(SDNode *N) {
+ SDValue N0 = N->getOperand(0);
+ ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
+ EVT VT = N->getValueType(0);
+
+ // fold (ffloor c1) -> ffloor(c1)
+ if (N0CFP && VT != MVT::ppcf128)
+ return DAG.getNode(ISD::FFLOOR, N->getDebugLoc(), VT, N0);
+
+ return SDValue();
+}
+
SDValue DAGCombiner::visitFABS(SDNode *N) {
SDValue N0 = N->getOperand(0);
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp?rev=161807&r1=161806&r2=161807&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp Mon Aug 13 18:32:49 2012
@@ -2483,6 +2483,24 @@
case ISD::FABS:
V.clearSign();
return getConstantFP(V, VT);
+ case ISD::FCEIL: {
+ APFloat::opStatus fs = V.roundToIntegral(APFloat::rmTowardPositive);
+ if (fs == APFloat::opOK || fs == APFloat::opInexact)
+ return getConstantFP(V, VT);
+ break;
+ }
+ case ISD::FTRUNC: {
+ APFloat::opStatus fs = V.roundToIntegral(APFloat::rmTowardZero);
+ if (fs == APFloat::opOK || fs == APFloat::opInexact)
+ return getConstantFP(V, VT);
+ break;
+ }
+ case ISD::FFLOOR: {
+ APFloat::opStatus fs = V.roundToIntegral(APFloat::rmTowardNegative);
+ if (fs == APFloat::opOK || fs == APFloat::opInexact)
+ return getConstantFP(V, VT);
+ break;
+ }
case ISD::FP_EXTEND: {
bool ignored;
// This can return overflow, underflow, or inexact; we don't care.
Modified: llvm/trunk/lib/Support/APFloat.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/APFloat.cpp?rev=161807&r1=161806&r2=161807&view=diff
==============================================================================
--- llvm/trunk/lib/Support/APFloat.cpp (original)
+++ llvm/trunk/lib/Support/APFloat.cpp Mon Aug 13 18:32:49 2012
@@ -1765,6 +1765,32 @@
return fs;
}
+/* Rounding-mode corrrect round to integral value. */
+APFloat::opStatus APFloat::roundToIntegral(roundingMode rounding_mode) {
+ opStatus fs;
+ assertArithmeticOK(*semantics);
+
+ // The algorithm here is quite simple: we add 2^(p-1), where p is the
+ // precision of our format, and then subtract it back off again. The choice
+ // of rounding modes for the addition/subtraction determines the rounding mode
+ // for our integral rounding as well.
+ APInt IntegerConstant(NextPowerOf2(semanticsPrecision(*semantics)),
+ 1 << (semanticsPrecision(*semantics)-1));
+ APFloat MagicConstant(*semantics);
+ fs = MagicConstant.convertFromAPInt(IntegerConstant, false,
+ rmNearestTiesToEven);
+ if (fs != opOK)
+ return fs;
+
+ fs = add(MagicConstant, rounding_mode);
+ if (fs != opOK && fs != opInexact)
+ return fs;
+
+ fs = subtract(MagicConstant, rounding_mode);
+ return fs;
+}
+
+
/* Comparison requires normalized numbers. */
APFloat::cmpResult
APFloat::compare(const APFloat &rhs) const
Added: llvm/trunk/test/CodeGen/ARM/floorf.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ARM/floorf.ll?rev=161807&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/ARM/floorf.ll (added)
+++ llvm/trunk/test/CodeGen/ARM/floorf.ll Mon Aug 13 18:32:49 2012
@@ -0,0 +1,29 @@
+; RUN: llc -march=arm < %s | FileCheck %s
+
+; CHECK: test1
+define float @test1() nounwind uwtable readnone ssp {
+; CHECK-NOT: floorf
+ %foo = call float @floorf(float 0x4000CCCCC0000000) nounwind readnone
+ ret float %foo
+}
+
+; CHECK: test2
+define float @test2() nounwind uwtable readnone ssp {
+; CHECK-NOT: ceilf
+ %foo = call float @ceilf(float 0x4000CCCCC0000000) nounwind readnone
+ ret float %foo
+}
+
+; CHECK: test3
+define float @test3() nounwind uwtable readnone ssp {
+; CHECK-NOT: truncf
+ %foo = call float @truncf(float 0x4000CCCCC0000000) nounwind readnone
+ ret float %foo
+}
+
+declare float @floorf(float) nounwind readnone
+declare float @ceilf(float) nounwind readnone
+declare float @truncf(float) nounwind readnone
+
+
+
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