Changes in directory llvm/lib/Target/SparcV8:
SparcV8ISelDAGToDAG.cpp updated: 1.70 -> 1.71
---
Log message:
Compile this:
void %X(int %A) {
%C = setlt int %A, 123 ; <bool> [#uses=1]
br bool %C, label %T, label %F
T: ; preds = %0
call int %main( int 0 ) ; <int>:0 [#uses=0]
ret void
F: ; preds = %0
ret void
}
to this:
X:
save -96, %o6, %o6
subcc %i0, 122, %l0
bg .LBBX_2 ! F
nop
...
not this:
X:
save -96, %o6, %o6
sethi 0, %l0
or %g0, 1, %l1
subcc %i0, 122, %l2
bg .LBBX_4 !
nop
.LBBX_3: !
or %g0, %l0, %l1
.LBBX_4: !
subcc %l1, 0, %l0
bne .LBBX_2 ! F
nop
---
Diffs of the changes: (+37 -21)
SparcV8ISelDAGToDAG.cpp | 58 ++++++++++++++++++++++++++++++------------------
1 files changed, 37 insertions(+), 21 deletions(-)
Index: llvm/lib/Target/SparcV8/SparcV8ISelDAGToDAG.cpp
diff -u llvm/lib/Target/SparcV8/SparcV8ISelDAGToDAG.cpp:1.70
llvm/lib/Target/SparcV8/SparcV8ISelDAGToDAG.cpp:1.71
--- llvm/lib/Target/SparcV8/SparcV8ISelDAGToDAG.cpp:1.70 Mon Jan 30
20:45:52 2006
+++ llvm/lib/Target/SparcV8/SparcV8ISelDAGToDAG.cpp Mon Jan 30 23:05:52 2006
@@ -735,6 +735,28 @@
abort();
}
+// Look at LHS/RHS/CC and see if they are a lowered V8 setcc instruction. If
so
+// set LHS/RHS and V8CC to the LHS/RHS of the setcc and V8CC to the condition.
+static void LookThroughSetCC(SDOperand &LHS, SDOperand &RHS,
+ ISD::CondCode CC, unsigned &V8CC) {
+ if (isa<ConstantSDNode>(RHS) && cast<ConstantSDNode>(RHS)->getValue() == 0 &&
+ CC == ISD::SETNE &&
+ ((LHS.getOpcode() == V8ISD::SELECT_ICC &&
+ LHS.getOperand(3).getOpcode() == V8ISD::CMPICC) ||
+ (LHS.getOpcode() == V8ISD::SELECT_FCC &&
+ LHS.getOperand(3).getOpcode() == V8ISD::CMPFCC)) &&
+ isa<ConstantSDNode>(LHS.getOperand(0)) &&
+ isa<ConstantSDNode>(LHS.getOperand(1)) &&
+ cast<ConstantSDNode>(LHS.getOperand(0))->getValue() == 1 &&
+ cast<ConstantSDNode>(LHS.getOperand(1))->getValue() == 0) {
+ SDOperand CMPCC = LHS.getOperand(3);
+ V8CC = cast<ConstantSDNode>(LHS.getOperand(2))->getValue();
+ LHS = CMPCC.getOperand(0);
+ RHS = CMPCC.getOperand(1);
+ }
+}
+
+
SDOperand SparcV8TargetLowering::
LowerOperation(SDOperand Op, SelectionDAG &DAG) {
switch (Op.getOpcode()) {
@@ -770,8 +792,14 @@
SDOperand LHS = Op.getOperand(2);
SDOperand RHS = Op.getOperand(3);
SDOperand Dest = Op.getOperand(4);
+ unsigned Opc, V8CC = ~0U;
+
+ // If this is a br_cc of a "setcc", and if the setcc got lowered into
+ // an CMP[IF]CC/SELECT_[IF]CC pair, find the original compared values.
+ LookThroughSetCC(LHS, RHS, CC, V8CC);
// Get the condition flag.
+ SDOperand CompareFlag;
if (LHS.getValueType() == MVT::i32) {
std::vector<MVT::ValueType> VTs;
VTs.push_back(MVT::i32);
@@ -779,14 +807,16 @@
std::vector<SDOperand> Ops;
Ops.push_back(LHS);
Ops.push_back(RHS);
- SDOperand Cond = DAG.getNode(V8ISD::CMPICC, VTs, Ops).getValue(1);
- SDOperand CCN = DAG.getConstant(IntCondCCodeToICC(CC), MVT::i32);
- return DAG.getNode(V8ISD::BRICC, MVT::Other, Chain, Dest, CCN, Cond);
+ CompareFlag = DAG.getNode(V8ISD::CMPICC, VTs, Ops).getValue(1);
+ if (V8CC == ~0U) V8CC = IntCondCCodeToICC(CC);
+ Opc = V8ISD::BRICC;
} else {
- SDOperand Cond = DAG.getNode(V8ISD::CMPFCC, MVT::Flag, LHS, RHS);
- SDOperand CCN = DAG.getConstant(FPCondCCodeToFCC(CC), MVT::i32);
- return DAG.getNode(V8ISD::BRFCC, MVT::Other, Chain, Dest, CCN, Cond);
+ CompareFlag = DAG.getNode(V8ISD::CMPFCC, MVT::Flag, LHS, RHS);
+ if (V8CC == ~0U) V8CC = FPCondCCodeToFCC(CC);
+ Opc = V8ISD::BRFCC;
}
+ return DAG.getNode(Opc, MVT::Other, Chain, Dest,
+ DAG.getConstant(V8CC, MVT::i32), CompareFlag);
}
case ISD::SELECT_CC: {
SDOperand LHS = Op.getOperand(0);
@@ -798,21 +828,7 @@
// If this is a select_cc of a "setcc", and if the setcc got lowered into
// an CMP[IF]CC/SELECT_[IF]CC pair, find the original compared values.
- if (isa<ConstantSDNode>(RHS) && cast<ConstantSDNode>(RHS)->getValue() ==
0&&
- CC == ISD::SETNE &&
- ((LHS.getOpcode() == V8ISD::SELECT_ICC &&
- LHS.getOperand(3).getOpcode() == V8ISD::CMPICC) ||
- (LHS.getOpcode() == V8ISD::SELECT_FCC &&
- LHS.getOperand(3).getOpcode() == V8ISD::CMPFCC)) &&
- isa<ConstantSDNode>(LHS.getOperand(0)) &&
- isa<ConstantSDNode>(LHS.getOperand(1)) &&
- cast<ConstantSDNode>(LHS.getOperand(0))->getValue() == 1 &&
- cast<ConstantSDNode>(LHS.getOperand(1))->getValue() == 0) {
- SDOperand CMPCC = LHS.getOperand(3);
- V8CC = cast<ConstantSDNode>(LHS.getOperand(2))->getValue();
- LHS = CMPCC.getOperand(0);
- RHS = CMPCC.getOperand(1);
- }
+ LookThroughSetCC(LHS, RHS, CC, V8CC);
SDOperand CompareFlag;
if (LHS.getValueType() == MVT::i32) {
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