ARM64: convert fp16 narrowing ISel to pseudo-instruction

The previous attempt was fine with optimisations, but was actually rather
cavalier with its types. When compiled at -O0, it produced invalid COPY
MachineInstrs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205422 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Tim Northover 2014-04-02 14:38:54 +00:00
parent 4e7ec2b053
commit 87e824120d
4 changed files with 16 additions and 15 deletions

View File

@ -624,6 +624,18 @@ bool ARM64ExpandPseudo::expandMI(MachineBasicBlock &MBB,
return true;
}
case ARM64::FCVTSHpseudo: {
MachineOperand Src = MI.getOperand(1);
Src.setImplicit();
unsigned SrcH = TII->getRegisterInfo().getSubReg(Src.getReg(), ARM64::hsub);
auto MIB = BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(ARM64::FCVTSHr))
.addOperand(MI.getOperand(0))
.addReg(SrcH, RegState::Undef)
.addOperand(Src);
transferImpOps(MI, MIB, MIB);
MI.eraseFromParent();
return true;
}
case ARM64::LOADgot: {
// Expand into ADRP + LDR.
unsigned DstReg = MI.getOperand(0).getReg();

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@ -1832,19 +1832,6 @@ SDNode *ARM64DAGToDAGISel::Select(SDNode *Node) {
break;
}
case ISD::FP16_TO_FP32: {
assert(Node->getOperand(0).getValueType() == MVT::i32 && "vector convert?");
EVT VT = Node->getValueType(0);
SDLoc DL(Node);
SDValue FPR32Id =
CurDAG->getTargetConstant(ARM64::FPR32RegClass.getID(), MVT::i32);
SDNode *Res =
CurDAG->getMachineNode(TargetOpcode::COPY_TO_REGCLASS, DL, MVT::i32,
Node->getOperand(0), FPR32Id);
SDValue FPR16Reg =
CurDAG->getTargetExtractSubreg(ARM64::hsub, DL, VT, SDValue(Res, 0));
return CurDAG->getMachineNode(ARM64::FCVTSHr, DL, VT, FPR16Reg);
}
case ISD::SRL:
case ISD::AND:
case ISD::SRA:

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@ -1927,6 +1927,8 @@ def : Pat<(f32_to_f16 FPR32:$Rn),
(f32 (SUBREG_TO_REG (i32 0), (FCVTHSr FPR32:$Rn), hsub)),
GPR32))>;
def FCVTSHpseudo : Pseudo<(outs FPR32:$Rd), (ins FPR32:$Rn),
[(set (f32 FPR32:$Rd), (f16_to_f32 i32:$Rn))]>;
//===----------------------------------------------------------------------===//
// Floating point single operand instructions.

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@ -1,4 +1,5 @@
; RUN: llc < %s -march=arm64 -arm64-neon-syntax=apple | FileCheck %s
; RUN: llc < %s -O0 -march=arm64 -arm64-neon-syntax=apple | FileCheck %s
define <2 x double> @test_vcvt_f64_f32(<2 x float> %x) nounwind readnone ssp {
; CHECK-LABEL: test_vcvt_f64_f32:
@ -64,8 +65,7 @@ declare <2 x float> @llvm.arm64.neon.fcvtxn.v2f32.v2f64(<2 x double>) nounwind r
define i16 @to_half(float %in) {
; CHECK-LABEL: to_half:
; CHECK: fcvt h[[HALFVAL:[0-9]+]], s0
; CHECK: fmov w0, s[[HALFVAL]]
; CHECK: fmov {{w[0-9]+}}, {{s[0-9]+}}
%res = call i16 @llvm.convert.to.fp16(float %in)
ret i16 %res
}