From 6269ed125fc492d81dc5e3f48482816fc9d47f49 Mon Sep 17 00:00:00 2001 From: Jim Laskey Date: Wed, 17 Aug 2005 00:39:29 +0000 Subject: [PATCH] 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 ; [#uses=1] ret double %tmp.1 } internal fastcc double %_Z2f2j(uint %x) { entry: %tmp.1 = cast uint %x to double ; [#uses=1] ret double %tmp.1 } internal fastcc float %_Z2f3i(int %x) { entry: %tmp.1 = cast int %x to float ; [#uses=1] ret float %tmp.1 } internal fastcc float %_Z2f4j(uint %x) { entry: %tmp.1 = cast uint %x to 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 ; [#uses=1] store uint 1127219200, uint* %tmp.0 %tmp.2 = cast int %x to uint ; [#uses=1] %tmp.3 = xor uint %tmp.2, 2147483648 ; [#uses=1] %tmp.5 = getelementptr [2 x uint]* %buffer, int 0, int 1 ; [#uses=1] store uint %tmp.3, uint* %tmp.5 %tmp.9 = cast [2 x uint]* %buffer to double* ; [#uses=1] %tmp.10 = load double* %tmp.9 ; [#uses=1] %tmp.13 = load double* cast (long* %signed_bias to double*) ; [#uses=1] %tmp.14 = sub double %tmp.10, %tmp.13 ; [#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 ; [#uses=1] store uint 1127219200, uint* %tmp.0 %tmp.1 = getelementptr [2 x uint]* %buffer, int 0, int 1 ; [#uses=1] store uint %x, uint* %tmp.1 %tmp.4 = cast [2 x uint]* %buffer to double* ; [#uses=1] %tmp.5 = load double* %tmp.4 ; [#uses=1] %tmp.8 = load double* cast (long* %unsigned_bias to double*) ; [#uses=1] %tmp.9 = sub double %tmp.5, %tmp.8 ; [#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 ; [#uses=1] store uint 1127219200, uint* %tmp.0 %tmp.2 = cast int %x to uint ; [#uses=1] %tmp.3 = xor uint %tmp.2, 2147483648 ; [#uses=1] %tmp.5 = getelementptr [2 x uint]* %buffer, int 0, int 1 ; [#uses=1] store uint %tmp.3, uint* %tmp.5 %tmp.9 = cast [2 x uint]* %buffer to double* ; [#uses=1] %tmp.10 = load double* %tmp.9 ; [#uses=1] %tmp.13 = load double* cast (long* %signed_bias to double*) ; [#uses=1] %tmp.14 = sub double %tmp.10, %tmp.13 ; [#uses=1] %tmp.16 = cast double %tmp.14 to 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 ; [#uses=1] store uint 1127219200, uint* %tmp.0 %tmp.1 = getelementptr [2 x uint]* %buffer, int 0, int 1 ; [#uses=1] store uint %x, uint* %tmp.1 %tmp.4 = cast [2 x uint]* %buffer to double* ; [#uses=1] %tmp.5 = load double* %tmp.4 ; [#uses=1] %tmp.8 = load double* cast (long* %unsigned_bias to double*) ; [#uses=1] %tmp.9 = sub double %tmp.5, %tmp.8 ; [#uses=1] %tmp.11 = cast double %tmp.9 to 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 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22814 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/SelectionDAG/LegalizeDAG.cpp | 83 ++++++++++++++++++++---- 1 file changed, 72 insertions(+), 11 deletions(-) diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp index 7bb4ce2565c..56f93adf9fb 100644 --- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp +++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp @@ -126,7 +126,9 @@ private: 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 @@ SelectionDAGLegalize::SelectionDAGLegalize(SelectionDAG &dag) "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 SelectionDAGLegalize::ExpandLegalUINT_TO_FP(SDOperand Op0, 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 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) { 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: