[RISCV] Add f16 to isFMAFasterThanFMulAndFAdd now that the Zfh extension is supported

This commit is contained in:
Craig Topper 2020-12-02 20:20:38 -08:00
parent 9bf0fea372
commit e52a91e156
3 changed files with 91 additions and 8 deletions

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@ -3499,6 +3499,8 @@ bool RISCVTargetLowering::isFMAFasterThanFMulAndFAdd(const MachineFunction &MF,
return false; return false;
switch (VT.getSimpleVT().SimpleTy) { switch (VT.getSimpleVT().SimpleTy) {
case MVT::f16:
return Subtarget.hasStdExtZfh();
case MVT::f32: case MVT::f32:
return Subtarget.hasStdExtF(); return Subtarget.hasStdExtF();
case MVT::f64: case MVT::f64:

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@ -321,3 +321,88 @@ define half @fnmsub_s(half %a, half %b, half %c) nounwind {
%1 = call half @llvm.fma.f16(half %nega, half %b, half %c) %1 = call half @llvm.fma.f16(half %nega, half %b, half %c)
ret half %1 ret half %1
} }
define half @fmadd_s_contract(half %a, half %b, half %c) nounwind {
; RV32IZFH-LABEL: fmadd_s_contract:
; RV32IZFH: # %bb.0:
; RV32IZFH-NEXT: fmadd.h fa0, fa0, fa1, fa2
; RV32IZFH-NEXT: ret
;
; RV64IZFH-LABEL: fmadd_s_contract:
; RV64IZFH: # %bb.0:
; RV64IZFH-NEXT: fmadd.h fa0, fa0, fa1, fa2
; RV64IZFH-NEXT: ret
%1 = fmul contract half %a, %b
%2 = fadd contract half %1, %c
ret half %2
}
define half @fmsub_s_contract(half %a, half %b, half %c) nounwind {
; RV32IZFH-LABEL: fmsub_s_contract:
; RV32IZFH: # %bb.0:
; RV32IZFH-NEXT: fmv.h.x ft0, zero
; RV32IZFH-NEXT: fadd.h ft0, fa2, ft0
; RV32IZFH-NEXT: fmsub.h fa0, fa0, fa1, ft0
; RV32IZFH-NEXT: ret
;
; RV64IZFH-LABEL: fmsub_s_contract:
; RV64IZFH: # %bb.0:
; RV64IZFH-NEXT: fmv.h.x ft0, zero
; RV64IZFH-NEXT: fadd.h ft0, fa2, ft0
; RV64IZFH-NEXT: fmsub.h fa0, fa0, fa1, ft0
; RV64IZFH-NEXT: ret
%c_ = fadd half 0.0, %c ; avoid negation using xor
%1 = fmul contract half %a, %b
%2 = fsub contract half %1, %c_
ret half %2
}
define half @fnmadd_s_contract(half %a, half %b, half %c) nounwind {
; RV32IZFH-LABEL: fnmadd_s_contract:
; RV32IZFH: # %bb.0:
; RV32IZFH-NEXT: fmv.h.x ft0, zero
; RV32IZFH-NEXT: fadd.h ft1, fa0, ft0
; RV32IZFH-NEXT: fadd.h ft2, fa1, ft0
; RV32IZFH-NEXT: fadd.h ft0, fa2, ft0
; RV32IZFH-NEXT: fnmadd.h fa0, ft1, ft2, ft0
; RV32IZFH-NEXT: ret
;
; RV64IZFH-LABEL: fnmadd_s_contract:
; RV64IZFH: # %bb.0:
; RV64IZFH-NEXT: fmv.h.x ft0, zero
; RV64IZFH-NEXT: fadd.h ft1, fa0, ft0
; RV64IZFH-NEXT: fadd.h ft2, fa1, ft0
; RV64IZFH-NEXT: fadd.h ft0, fa2, ft0
; RV64IZFH-NEXT: fnmadd.h fa0, ft1, ft2, ft0
; RV64IZFH-NEXT: ret
%a_ = fadd half 0.0, %a ; avoid negation using xor
%b_ = fadd half 0.0, %b ; avoid negation using xor
%c_ = fadd half 0.0, %c ; avoid negation using xor
%1 = fmul contract half %a_, %b_
%2 = fneg half %1
%3 = fsub contract half %2, %c_
ret half %3
}
define half @fnmsub_s_contract(half %a, half %b, half %c) nounwind {
; RV32IZFH-LABEL: fnmsub_s_contract:
; RV32IZFH: # %bb.0:
; RV32IZFH-NEXT: fmv.h.x ft0, zero
; RV32IZFH-NEXT: fadd.h ft1, fa0, ft0
; RV32IZFH-NEXT: fadd.h ft0, fa1, ft0
; RV32IZFH-NEXT: fnmsub.h fa0, ft1, ft0, fa2
; RV32IZFH-NEXT: ret
;
; RV64IZFH-LABEL: fnmsub_s_contract:
; RV64IZFH: # %bb.0:
; RV64IZFH-NEXT: fmv.h.x ft0, zero
; RV64IZFH-NEXT: fadd.h ft1, fa0, ft0
; RV64IZFH-NEXT: fadd.h ft0, fa1, ft0
; RV64IZFH-NEXT: fnmsub.h fa0, ft1, ft0, fa2
; RV64IZFH-NEXT: ret
%a_ = fadd half 0.0, %a ; avoid negation using xor
%b_ = fadd half 0.0, %b ; avoid negation using xor
%1 = fmul contract half %a_, %b_
%2 = fsub contract half %c, %1
ret half %2
}

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@ -65,26 +65,22 @@ declare half @llvm.fmuladd.f16(half, half, half)
define half @fmuladd_f16(half %a, half %b, half %c) nounwind { define half @fmuladd_f16(half %a, half %b, half %c) nounwind {
; RV32IZFH-LABEL: fmuladd_f16: ; RV32IZFH-LABEL: fmuladd_f16:
; RV32IZFH: # %bb.0: ; RV32IZFH: # %bb.0:
; RV32IZFH-NEXT: fmul.h ft0, fa0, fa1 ; RV32IZFH-NEXT: fmadd.h fa0, fa0, fa1, fa2
; RV32IZFH-NEXT: fadd.h fa0, ft0, fa2
; RV32IZFH-NEXT: ret ; RV32IZFH-NEXT: ret
; ;
; RV32IDZFH-LABEL: fmuladd_f16: ; RV32IDZFH-LABEL: fmuladd_f16:
; RV32IDZFH: # %bb.0: ; RV32IDZFH: # %bb.0:
; RV32IDZFH-NEXT: fmul.h ft0, fa0, fa1 ; RV32IDZFH-NEXT: fmadd.h fa0, fa0, fa1, fa2
; RV32IDZFH-NEXT: fadd.h fa0, ft0, fa2
; RV32IDZFH-NEXT: ret ; RV32IDZFH-NEXT: ret
; ;
; RV64IZFH-LABEL: fmuladd_f16: ; RV64IZFH-LABEL: fmuladd_f16:
; RV64IZFH: # %bb.0: ; RV64IZFH: # %bb.0:
; RV64IZFH-NEXT: fmul.h ft0, fa0, fa1 ; RV64IZFH-NEXT: fmadd.h fa0, fa0, fa1, fa2
; RV64IZFH-NEXT: fadd.h fa0, ft0, fa2
; RV64IZFH-NEXT: ret ; RV64IZFH-NEXT: ret
; ;
; RV64IDZFH-LABEL: fmuladd_f16: ; RV64IDZFH-LABEL: fmuladd_f16:
; RV64IDZFH: # %bb.0: ; RV64IDZFH: # %bb.0:
; RV64IDZFH-NEXT: fmul.h ft0, fa0, fa1 ; RV64IDZFH-NEXT: fmadd.h fa0, fa0, fa1, fa2
; RV64IDZFH-NEXT: fadd.h fa0, ft0, fa2
; RV64IDZFH-NEXT: ret ; RV64IDZFH-NEXT: ret
%1 = call half @llvm.fmuladd.f16(half %a, half %b, half %c) %1 = call half @llvm.fmuladd.f16(half %a, half %b, half %c)
ret half %1 ret half %1