Make it possible for ints/floats to return different values from getBooleanContents()
Summary:
On MIPS32r6/MIPS64r6, floating point comparisons return 0 or -1 but integer
comparisons return 0 or 1.
Updated the various uses of getBooleanContents. Two simplifications had to be
disabled when float and int boolean contents differ:
- ScalarizeVecRes_VSELECT except when the kind of boolean contents is trivially
discoverable (i.e. when the condition of the VSELECT is a SETCC node).
- visitVSELECT (select C, 0, 1) -> (xor C, 1).
Come to think of it, this one could test for the common case of 'C'
being a SETCC too.
Preserved existing behaviour for all other targets and updated the affected
MIPS32r6/MIPS64r6 tests. This also fixes the pi benchmark where the 'low'
variable was counting in the wrong direction because it thought it could simply
add the result of the comparison.
Reviewers: hfinkel
Reviewed By: hfinkel
Subscribers: hfinkel, jholewinski, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D4389
llvm-svn: 212697
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 1df041d..df27365 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -3958,14 +3958,14 @@
// If setcc produces all-one true value then:
// (shl (and (setcc) N01CV) N1CV) -> (and (setcc) N01CV<<N1CV)
if (N1CV && N1CV->isConstant()) {
- if (N0.getOpcode() == ISD::AND &&
- TLI.getBooleanContents(true) ==
- TargetLowering::ZeroOrNegativeOneBooleanContent) {
+ if (N0.getOpcode() == ISD::AND) {
SDValue N00 = N0->getOperand(0);
SDValue N01 = N0->getOperand(1);
BuildVectorSDNode *N01CV = dyn_cast<BuildVectorSDNode>(N01);
- if (N01CV && N01CV->isConstant() && N00.getOpcode() == ISD::SETCC) {
+ if (N01CV && N01CV->isConstant() && N00.getOpcode() == ISD::SETCC &&
+ TLI.getBooleanContents(N00.getOperand(0).getValueType()) ==
+ TargetLowering::ZeroOrNegativeOneBooleanContent) {
SDValue C = DAG.FoldConstantArithmetic(ISD::SHL, VT, N01CV, N1CV);
if (C.getNode())
return DAG.getNode(ISD::AND, SDLoc(N), VT, N00, C);
@@ -4524,11 +4524,20 @@
if (VT == MVT::i1 && N1C && N1C->getAPIntValue() == 1)
return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N2);
// fold (select C, 0, 1) -> (xor C, 1)
+ // We can't do this reliably if integer based booleans have different contents
+ // to floating point based booleans. This is because we can't tell whether we
+ // have an integer-based boolean or a floating-point-based boolean unless we
+ // can find the SETCC that produced it and inspect its operands. This is
+ // fairly easy if C is the SETCC node, but it can potentially be
+ // undiscoverable (or not reasonably discoverable). For example, it could be
+ // in another basic block or it could require searching a complicated
+ // expression.
if (VT.isInteger() &&
- (VT0 == MVT::i1 ||
- (VT0.isInteger() &&
- TLI.getBooleanContents(false) ==
- TargetLowering::ZeroOrOneBooleanContent)) &&
+ (VT0 == MVT::i1 || (VT0.isInteger() &&
+ TLI.getBooleanContents(false, false) ==
+ TLI.getBooleanContents(false, true) &&
+ TLI.getBooleanContents(false, false) ==
+ TargetLowering::ZeroOrOneBooleanContent)) &&
N1C && N2C && N1C->isNullValue() && N2C->getAPIntValue() == 1) {
SDValue XORNode;
if (VT == VT0)
@@ -5077,12 +5086,12 @@
}
if (N0.getOpcode() == ISD::SETCC) {
+ EVT N0VT = N0.getOperand(0).getValueType();
// sext(setcc) -> sext_in_reg(vsetcc) for vectors.
// Only do this before legalize for now.
if (VT.isVector() && !LegalOperations &&
- TLI.getBooleanContents(true) ==
- TargetLowering::ZeroOrNegativeOneBooleanContent) {
- EVT N0VT = N0.getOperand(0).getValueType();
+ TLI.getBooleanContents(N0VT) ==
+ TargetLowering::ZeroOrNegativeOneBooleanContent) {
// On some architectures (such as SSE/NEON/etc) the SETCC result type is
// of the same size as the compared operands. Only optimize sext(setcc())
// if this is the case.
@@ -11243,8 +11252,8 @@
// fold select C, 16, 0 -> shl C, 4
if (N2C && N3C && N3C->isNullValue() && N2C->getAPIntValue().isPowerOf2() &&
- TLI.getBooleanContents(N0.getValueType().isVector()) ==
- TargetLowering::ZeroOrOneBooleanContent) {
+ TLI.getBooleanContents(N0.getValueType()) ==
+ TargetLowering::ZeroOrOneBooleanContent) {
// If the caller doesn't want us to simplify this into a zext of a compare,
// don't do it.