711e5cd644
The x86_divmodx traps on integer overflow, but the srem instruction is not supposed to trap with a -1 divisor. Generate a legalization expansion for srem that special-cases the -1 divisor to simply return 0.
103 lines
2.9 KiB
Python
103 lines
2.9 KiB
Python
"""
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Custom legalization patterns for Intel.
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"""
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from __future__ import absolute_import
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from cdsl.ast import Var
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from cdsl.xform import Rtl, XFormGroup
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from base.immediates import imm64, floatcc
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from base.types import i32, i64
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from base import legalize as shared
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from base import instructions as insts
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from . import instructions as x86
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from .defs import ISA
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intel_expand = XFormGroup(
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'intel_expand',
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"""
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Legalize instructions by expansion.
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Use Intel-specific instructions if needed.
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""",
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isa=ISA, chain=shared.expand)
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a = Var('a')
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dead = Var('dead')
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x = Var('x')
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xhi = Var('xhi')
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y = Var('y')
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a1 = Var('a1')
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a2 = Var('a2')
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#
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# Division and remainder.
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#
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intel_expand.legalize(
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a << insts.udiv(x, y),
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Rtl(
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xhi << insts.iconst(imm64(0)),
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(a, dead) << x86.udivmodx(x, xhi, y)
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))
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intel_expand.legalize(
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a << insts.urem(x, y),
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Rtl(
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xhi << insts.iconst(imm64(0)),
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(dead, a) << x86.udivmodx(x, xhi, y)
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))
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for ty in [i32, i64]:
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intel_expand.legalize(
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a << insts.sdiv.bind(ty)(x, y),
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Rtl(
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xhi << insts.sshr_imm(x, imm64(ty.lane_bits() - 1)),
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(a, dead) << x86.sdivmodx(x, xhi, y)
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))
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# The srem expansion requires custom code because srem INT_MIN, -1 is not
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# allowed to trap.
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intel_expand.custom_legalize(insts.srem, 'expand_srem')
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# Floating point condition codes.
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#
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# The 8 condition codes in `supported_floatccs` are directly supported by a
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# `ucomiss` or `ucomisd` instruction. The remaining codes need legalization
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# patterns.
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# Equality needs an explicit `ord` test which checks the parity bit.
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intel_expand.legalize(
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a << insts.fcmp(floatcc.eq, x, y),
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Rtl(
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a1 << insts.fcmp(floatcc.ord, x, y),
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a2 << insts.fcmp(floatcc.ueq, x, y),
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a << insts.band(a1, a2)
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))
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intel_expand.legalize(
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a << insts.fcmp(floatcc.ne, x, y),
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Rtl(
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a1 << insts.fcmp(floatcc.uno, x, y),
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a2 << insts.fcmp(floatcc.one, x, y),
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a << insts.bor(a1, a2)
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))
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# Inequalities that need to be reversed.
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for cc, rev_cc in [
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(floatcc.lt, floatcc.gt),
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(floatcc.le, floatcc.ge),
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(floatcc.ugt, floatcc.ult),
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(floatcc.uge, floatcc.ule)]:
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intel_expand.legalize(
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a << insts.fcmp(cc, x, y),
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Rtl(
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a << insts.fcmp(rev_cc, y, x)
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))
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# We need to modify the CFG for min/max legalization.
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intel_expand.custom_legalize(insts.fmin, 'expand_minmax')
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intel_expand.custom_legalize(insts.fmax, 'expand_minmax')
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# Conversions from unsigned need special handling.
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intel_expand.custom_legalize(insts.fcvt_from_uint, 'expand_fcvt_from_uint')
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# Conversions from float to int can trap.
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intel_expand.custom_legalize(insts.fcvt_to_sint, 'expand_fcvt_to_sint')
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intel_expand.custom_legalize(insts.fcvt_to_uint, 'expand_fcvt_to_uint')
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