reapply my previous patch (r66358) with a tweak to set the
alignment of the generated constant pool entry to the
desired alignment of a type. If we don't do this, we end up
trying to do movsd from 4-byte alignment memory. This fixes
450.soplex and 456.hmmer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66641 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index e2d128a..993092e 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -14,8 +14,10 @@
#define DEBUG_TYPE "dagcombine"
#include "llvm/CodeGen/SelectionDAG.h"
+#include "llvm/DerivedTypes.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetFrameInfo.h"
@@ -2891,8 +2893,7 @@
return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT,
N0.getOperand(0), N0.getOperand(1),
N1, N2, N0.getOperand(2));
- else
- return SimplifySelect(N->getDebugLoc(), N0, N1, N2);
+ return SimplifySelect(N->getDebugLoc(), N0, N1, N2);
}
return SDValue();
@@ -5675,9 +5676,14 @@
return false;
}
+/// SimplifySelectCC - Simplify an expression of the form (N0 cond N1) ? N2 : N3
+/// where 'cond' is the comparison specified by CC.
SDValue DAGCombiner::SimplifySelectCC(DebugLoc DL, SDValue N0, SDValue N1,
SDValue N2, SDValue N3,
ISD::CondCode CC, bool NotExtCompare) {
+ // (x ? y : y) -> y.
+ if (N2 == N3) return N2;
+
MVT VT = N2.getValueType();
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.getNode());
@@ -5713,6 +5719,53 @@
return DAG.getNode(ISD::FABS, DL, VT, N3);
}
}
+
+ // Turn "(a cond b) ? 1.0f : 2.0f" into "load (tmp + ((a cond b) ? 0 : 4)"
+ // where "tmp" is a constant pool entry containing an array with 1.0 and 2.0
+ // in it. This is a win when the constant is not otherwise available because
+ // it replaces two constant pool loads with one. We only do this if the FP
+ // type is known to be legal, because if it isn't, then we are before legalize
+ // types an we want the other legalization to happen first (e.g. to avoid
+ // messing with soft float).
+ if (ConstantFPSDNode *TV = dyn_cast<ConstantFPSDNode>(N2))
+ if (ConstantFPSDNode *FV = dyn_cast<ConstantFPSDNode>(N3)) {
+ if (TLI.isTypeLegal(N2.getValueType()) &&
+ // If both constants have multiple uses, then we won't need to do an
+ // extra load, they are likely around in registers for other users.
+ (TV->hasOneUse() || FV->hasOneUse())) {
+ Constant *Elts[] = {
+ const_cast<ConstantFP*>(FV->getConstantFPValue()),
+ const_cast<ConstantFP*>(TV->getConstantFPValue())
+ };
+ const Type *FPTy = Elts[0]->getType();
+ const TargetData &TD = *TLI.getTargetData();
+
+ // Create a ConstantArray of the two constants.
+ Constant *CA = ConstantArray::get(ArrayType::get(FPTy, 2), Elts, 2);
+ SDValue CPIdx = DAG.getConstantPool(CA, TLI.getPointerTy(),
+ TD.getPrefTypeAlignment(FPTy));
+ unsigned Alignment =
+ 1 << cast<ConstantPoolSDNode>(CPIdx)->getAlignment();
+
+ // Get the offsets to the 0 and 1 element of the array so that we can
+ // select between them.
+ SDValue Zero = DAG.getIntPtrConstant(0);
+ unsigned EltSize = (unsigned)TD.getTypePaddedSize(Elts[0]->getType());
+ SDValue One = DAG.getIntPtrConstant(EltSize);
+
+ SDValue Cond = DAG.getSetCC(DL,
+ TLI.getSetCCResultType(N0.getValueType()),
+ N0, N1, CC);
+ SDValue CstOffset = DAG.getNode(ISD::SELECT, DL, Zero.getValueType(),
+ Cond, One, Zero);
+ CPIdx = DAG.getNode(ISD::ADD, DL, TLI.getPointerTy(), CPIdx,
+ CstOffset);
+ return DAG.getLoad(TV->getValueType(0), DL, DAG.getEntryNode(), CPIdx,
+ PseudoSourceValue::getConstantPool(), 0, false,
+ Alignment);
+
+ }
+ }
// Check to see if we can perform the "gzip trick", transforming
// (select_cc setlt X, 0, A, 0) -> (and (sra X, (sub size(X), 1), A)