[llvm-commits] CVS: llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
Jim Laskey
jlaskey at apple.com
Tue Aug 16 17:39:40 PDT 2005
Changes in directory llvm/lib/CodeGen/SelectionDAG:
LegalizeDAG.cpp updated: 1.163 -> 1.164
---
Log message:
Added generic code expansion for [signed|unsigned] i32 to [f32|f64] casts in the
legalizer. PowerPC now uses this expansion instead of ISel version.
Example:
// signed integer to double conversion
double f1(signed x) {
return (double)x;
}
// unsigned integer to double conversion
double f2(unsigned x) {
return (double)x;
}
// signed integer to float conversion
float f3(signed x) {
return (float)x;
}
// unsigned integer to float conversion
float f4(unsigned x) {
return (float)x;
}
Byte Code:
internal fastcc double %_Z2f1i(int %x) {
entry:
%tmp.1 = cast int %x to double ; <double> [#uses=1]
ret double %tmp.1
}
internal fastcc double %_Z2f2j(uint %x) {
entry:
%tmp.1 = cast uint %x to double ; <double> [#uses=1]
ret double %tmp.1
}
internal fastcc float %_Z2f3i(int %x) {
entry:
%tmp.1 = cast int %x to float ; <float> [#uses=1]
ret float %tmp.1
}
internal fastcc float %_Z2f4j(uint %x) {
entry:
%tmp.1 = cast uint %x to float ; <float> [#uses=1]
ret float %tmp.1
}
internal fastcc double %_Z2g1i(int %x) {
entry:
%buffer = alloca [2 x uint] ; <[2 x uint]*> [#uses=3]
%tmp.0 = getelementptr [2 x uint]* %buffer, int 0, int 0 ; <uint*> [#uses=1]
store uint 1127219200, uint* %tmp.0
%tmp.2 = cast int %x to uint ; <uint> [#uses=1]
%tmp.3 = xor uint %tmp.2, 2147483648 ; <uint> [#uses=1]
%tmp.5 = getelementptr [2 x uint]* %buffer, int 0, int 1 ; <uint*> [#uses=1]
store uint %tmp.3, uint* %tmp.5
%tmp.9 = cast [2 x uint]* %buffer to double* ; <double*> [#uses=1]
%tmp.10 = load double* %tmp.9 ; <double> [#uses=1]
%tmp.13 = load double* cast (long* %signed_bias to double*) ; <double> [#uses=1]
%tmp.14 = sub double %tmp.10, %tmp.13 ; <double> [#uses=1]
ret double %tmp.14
}
internal fastcc double %_Z2g2j(uint %x) {
entry:
%buffer = alloca [2 x uint] ; <[2 x uint]*> [#uses=3]
%tmp.0 = getelementptr [2 x uint]* %buffer, int 0, int 0 ; <uint*> [#uses=1]
store uint 1127219200, uint* %tmp.0
%tmp.1 = getelementptr [2 x uint]* %buffer, int 0, int 1 ; <uint*> [#uses=1]
store uint %x, uint* %tmp.1
%tmp.4 = cast [2 x uint]* %buffer to double* ; <double*> [#uses=1]
%tmp.5 = load double* %tmp.4 ; <double> [#uses=1]
%tmp.8 = load double* cast (long* %unsigned_bias to double*) ; <double> [#uses=1]
%tmp.9 = sub double %tmp.5, %tmp.8 ; <double> [#uses=1]
ret double %tmp.9
}
internal fastcc float %_Z2g3i(int %x) {
entry:
%buffer = alloca [2 x uint] ; <[2 x uint]*> [#uses=3]
%tmp.0 = getelementptr [2 x uint]* %buffer, int 0, int 0 ; <uint*> [#uses=1]
store uint 1127219200, uint* %tmp.0
%tmp.2 = cast int %x to uint ; <uint> [#uses=1]
%tmp.3 = xor uint %tmp.2, 2147483648 ; <uint> [#uses=1]
%tmp.5 = getelementptr [2 x uint]* %buffer, int 0, int 1 ; <uint*> [#uses=1]
store uint %tmp.3, uint* %tmp.5
%tmp.9 = cast [2 x uint]* %buffer to double* ; <double*> [#uses=1]
%tmp.10 = load double* %tmp.9 ; <double> [#uses=1]
%tmp.13 = load double* cast (long* %signed_bias to double*) ; <double> [#uses=1]
%tmp.14 = sub double %tmp.10, %tmp.13 ; <double> [#uses=1]
%tmp.16 = cast double %tmp.14 to float ; <float> [#uses=1]
ret float %tmp.16
}
internal fastcc float %_Z2g4j(uint %x) {
entry:
%buffer = alloca [2 x uint] ; <[2 x uint]*> [#uses=3]
%tmp.0 = getelementptr [2 x uint]* %buffer, int 0, int 0 ; <uint*> [#uses=1]
store uint 1127219200, uint* %tmp.0
%tmp.1 = getelementptr [2 x uint]* %buffer, int 0, int 1 ; <uint*> [#uses=1]
store uint %x, uint* %tmp.1
%tmp.4 = cast [2 x uint]* %buffer to double* ; <double*> [#uses=1]
%tmp.5 = load double* %tmp.4 ; <double> [#uses=1]
%tmp.8 = load double* cast (long* %unsigned_bias to double*) ; <double> [#uses=1]
%tmp.9 = sub double %tmp.5, %tmp.8 ; <double> [#uses=1]
%tmp.11 = cast double %tmp.9 to float ; <float> [#uses=1]
ret float %tmp.11
}
PowerPC Code:
.machine ppc970
.const
.align 2
.CPIl1__Z2f1i_0: ; float 0x4330000080000000
.long 1501560836 ; float 4.5036e+15
.text
.align 2
.globl l1__Z2f1i
l1__Z2f1i:
.LBBl1__Z2f1i_0: ; entry
xoris r2, r3, 32768
stw r2, -4(r1)
lis r2, 17200
stw r2, -8(r1)
lfd f0, -8(r1)
lis r2, ha16(.CPIl1__Z2f1i_0)
lfs f1, lo16(.CPIl1__Z2f1i_0)(r2)
fsub f1, f0, f1
blr
.const
.align 2
.CPIl2__Z2f2j_0: ; float 0x4330000000000000
.long 1501560832 ; float 4.5036e+15
.text
.align 2
.globl l2__Z2f2j
l2__Z2f2j:
.LBBl2__Z2f2j_0: ; entry
stw r3, -4(r1)
lis r2, 17200
stw r2, -8(r1)
lfd f0, -8(r1)
lis r2, ha16(.CPIl2__Z2f2j_0)
lfs f1, lo16(.CPIl2__Z2f2j_0)(r2)
fsub f1, f0, f1
blr
.const
.align 2
.CPIl3__Z2f3i_0: ; float 0x4330000080000000
.long 1501560836 ; float 4.5036e+15
.text
.align 2
.globl l3__Z2f3i
l3__Z2f3i:
.LBBl3__Z2f3i_0: ; entry
xoris r2, r3, 32768
stw r2, -4(r1)
lis r2, 17200
stw r2, -8(r1)
lfd f0, -8(r1)
lis r2, ha16(.CPIl3__Z2f3i_0)
lfs f1, lo16(.CPIl3__Z2f3i_0)(r2)
fsub f0, f0, f1
frsp f1, f0
blr
.const
.align 2
.CPIl4__Z2f4j_0: ; float 0x4330000000000000
.long 1501560832 ; float 4.5036e+15
.text
.align 2
.globl l4__Z2f4j
l4__Z2f4j:
.LBBl4__Z2f4j_0: ; entry
stw r3, -4(r1)
lis r2, 17200
stw r2, -8(r1)
lfd f0, -8(r1)
lis r2, ha16(.CPIl4__Z2f4j_0)
lfs f1, lo16(.CPIl4__Z2f4j_0)(r2)
fsub f0, f0, f1
frsp f1, f0
blr
---
Diffs of the changes: (+72 -11)
LegalizeDAG.cpp | 83 ++++++++++++++++++++++++++++++++++++++++++++++++--------
1 files changed, 72 insertions(+), 11 deletions(-)
Index: llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
diff -u llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp:1.163 llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp:1.164
--- llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp:1.163 Tue Aug 16 16:55:35 2005
+++ llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp Tue Aug 16 19:39:29 2005
@@ -126,7 +126,9 @@
SDOperand ExpandIntToFP(bool isSigned, MVT::ValueType DestTy,
SDOperand Source);
- SDOperand ExpandLegalUINT_TO_FP(SDOperand LegalOp, MVT::ValueType DestVT);
+ SDOperand ExpandLegalINT_TO_FP(bool isSigned,
+ SDOperand LegalOp,
+ MVT::ValueType DestVT);
SDOperand PromoteLegalINT_TO_FP(SDOperand LegalOp, MVT::ValueType DestVT,
bool isSigned);
SDOperand PromoteLegalFP_TO_INT(SDOperand LegalOp, MVT::ValueType DestVT,
@@ -155,12 +157,71 @@
"Too many value types for ValueTypeActions to hold!");
}
-/// ExpandLegalUINT_TO_FP - This function is responsible for legalizing a
-/// UINT_TO_FP operation of the specified operand when the target requests that
+/// ExpandLegalINT_TO_FP - This function is responsible for legalizing a
+/// INT_TO_FP operation of the specified operand when the target requests that
/// we expand it. At this point, we know that the result and operand types are
/// legal for the target.
-SDOperand SelectionDAGLegalize::ExpandLegalUINT_TO_FP(SDOperand Op0,
- MVT::ValueType DestVT) {
+SDOperand SelectionDAGLegalize::ExpandLegalINT_TO_FP(bool isSigned,
+ SDOperand Op0,
+ MVT::ValueType DestVT) {
+ if (Op0.getValueType() == MVT::i32) {
+ // simple 32-bit [signed|unsigned] integer to float/double expansion
+
+ // get the stack frame index of a 8 byte buffer
+ MachineFunction &MF = DAG.getMachineFunction();
+ int SSFI = MF.getFrameInfo()->CreateStackObject(8, 8);
+ // get address of 8 byte buffer
+ SDOperand StackSlot = DAG.getFrameIndex(SSFI, TLI.getPointerTy());
+ // word offset constant for Hi/Lo address computation
+ SDOperand WordOff = DAG.getConstant(sizeof(int), TLI.getPointerTy());
+ // set up Hi and Lo (into buffer) address based on endian
+ SDOperand Hi, Lo;
+ if (TLI.isLittleEndian()) {
+ Hi = DAG.getNode(ISD::ADD, TLI.getPointerTy(), StackSlot, WordOff);
+ Lo = StackSlot;
+ } else {
+ Hi = StackSlot;
+ Lo = DAG.getNode(ISD::ADD, TLI.getPointerTy(), StackSlot, WordOff);
+ }
+ // if signed map to unsigned space
+ SDOperand Op0Mapped;
+ if (isSigned) {
+ // constant used to invert sign bit (signed to unsigned mapping)
+ SDOperand SignBit = DAG.getConstant(0x80000000u, MVT::i32);
+ Op0Mapped = DAG.getNode(ISD::XOR, MVT::i32, Op0, SignBit);
+ } else {
+ Op0Mapped = Op0;
+ }
+ // store the lo of the constructed double - based on integer input
+ SDOperand Store1 = DAG.getNode(ISD::STORE, MVT::Other, DAG.getEntryNode(),
+ Op0Mapped, Lo, DAG.getSrcValue(NULL));
+ // initial hi portion of constructed double
+ SDOperand InitialHi = DAG.getConstant(0x43300000u, MVT::i32);
+ // store the hi of the constructed double - biased exponent
+ SDOperand Store2 = DAG.getNode(ISD::STORE, MVT::Other, Store1,
+ InitialHi, Hi, DAG.getSrcValue(NULL));
+ // load the constructed double
+ SDOperand Load = DAG.getLoad(MVT::f64, Store2, StackSlot,
+ DAG.getSrcValue(NULL));
+ // FP constant to bias correct the final result
+ SDOperand Bias = DAG.getConstantFP(isSigned ? 0x1.000008p52 : 0x1.000000p52,
+ MVT::f64);
+ // subtract the bias
+ SDOperand Sub = DAG.getNode(ISD::SUB, MVT::f64, Load, Bias);
+ // final result
+ SDOperand Result;
+ // handle final rounding
+ if (DestVT == MVT::f64) {
+ // do nothing
+ Result = Sub;
+ } else {
+ // if f32 then cast to f32
+ Result = DAG.getNode(ISD::FP_ROUND, MVT::f32, Sub);
+ }
+ NeedsAnotherIteration = true;
+ return Result;
+ }
+ assert(!isSigned && "Legalize cannot Expand SINT_TO_FP for i64 yet");
SDOperand Tmp1 = DAG.getNode(ISD::SINT_TO_FP, DestVT, Op0);
SDOperand SignSet = DAG.getSetCC(TLI.getSetCCResultTy(), Op0,
@@ -170,9 +231,9 @@
SDOperand CstOffset = DAG.getNode(ISD::SELECT, Zero.getValueType(),
SignSet, Four, Zero);
- // If the sign bit of the integer is set, the large number will be treated as
- // a negative number. To counteract this, the dynamic code adds an offset
- // depending on the data type.
+ // If the sign bit of the integer is set, the large number will be treated
+ // as a negative number. To counteract this, the dynamic code adds an
+ // offset depending on the data type.
uint64_t FF;
switch (Op0.getValueType()) {
default: assert(0 && "Unsupported integer type!");
@@ -1648,9 +1709,9 @@
Node->getOperand(0).getValueType())) {
default: assert(0 && "Unknown operation action!");
case TargetLowering::Expand:
- assert(!isSigned && "Legalize cannot Expand SINT_TO_FP yet");
- Result = ExpandLegalUINT_TO_FP(LegalizeOp(Node->getOperand(0)),
- Node->getValueType(0));
+ Result = ExpandLegalINT_TO_FP(isSigned,
+ LegalizeOp(Node->getOperand(0)),
+ Node->getValueType(0));
AddLegalizedOperand(Op, Result);
return Result;
case TargetLowering::Promote:
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