Files
wasmtime/lib/cretonne/meta/isa/intel/legalize.py
Jakob Stoklund Olesen 7fb6159a85 Add Intel encodings for the fcmp instruction.
Not all floating point condition codes are directly supported by the
ucimiss/ucomisd instructions. Some inequalities need to be reversed and
eq+ne require two separate tests.
2017-09-26 11:17:32 -07:00

95 lines
2.5 KiB
Python

"""
Custom legalization patterns for Intel.
"""
from __future__ import absolute_import
from cdsl.ast import Var
from cdsl.xform import Rtl, XFormGroup
from base.immediates import imm64, floatcc
from base.types import i32, i64
from base import legalize as shared
from base import instructions as insts
from . import instructions as x86
from .defs import ISA
intel_expand = XFormGroup(
'intel_expand',
"""
Legalize instructions by expansion.
Use Intel-specific instructions if needed.
""",
isa=ISA, chain=shared.expand)
a = Var('a')
dead = Var('dead')
x = Var('x')
xhi = Var('xhi')
y = Var('y')
a1 = Var('a1')
a2 = Var('a2')
#
# Division and remainder.
#
intel_expand.legalize(
a << insts.udiv(x, y),
Rtl(
xhi << insts.iconst(imm64(0)),
(a, dead) << x86.udivmodx(x, xhi, y)
))
intel_expand.legalize(
a << insts.urem(x, y),
Rtl(
xhi << insts.iconst(imm64(0)),
(dead, a) << x86.udivmodx(x, xhi, y)
))
for ty in [i32, i64]:
intel_expand.legalize(
a << insts.sdiv.bind(ty)(x, y),
Rtl(
xhi << insts.sshr_imm(x, imm64(ty.lane_bits() - 1)),
(a, dead) << x86.sdivmodx(x, xhi, y)
))
intel_expand.legalize(
a << insts.srem.bind(ty)(x, y),
Rtl(
xhi << insts.sshr_imm(x, imm64(ty.lane_bits() - 1)),
(dead, a) << x86.sdivmodx(x, xhi, y)
))
# Floating point condition codes.
#
# The 8 condition codes in `supported_floatccs` are directly supported by a
# `ucomiss` or `ucomisd` instruction. The remaining codes need legalization
# patterns.
# Equality needs an explicit `ord` test which checks the parity bit.
intel_expand.legalize(
a << insts.fcmp(floatcc.eq, x, y),
Rtl(
a1 << insts.fcmp(floatcc.ord, x, y),
a2 << insts.fcmp(floatcc.ueq, x, y),
a << insts.band(a1, a2)
))
intel_expand.legalize(
a << insts.fcmp(floatcc.ne, x, y),
Rtl(
a1 << insts.fcmp(floatcc.uno, x, y),
a2 << insts.fcmp(floatcc.one, x, y),
a << insts.bor(a1, a2)
))
# Inequalities that need to be reversed.
for cc, rev_cc in [
(floatcc.lt, floatcc.gt),
(floatcc.le, floatcc.ge),
(floatcc.ugt, floatcc.ult),
(floatcc.uge, floatcc.ule)]:
intel_expand.legalize(
a << insts.fcmp(cc, x, y),
Rtl(
a << insts.fcmp(rev_cc, y, x)
))