llvm-project/llvm/lib/Target/AMDGPU/AMDGPUCombine.td

//=- AMDGPUCombine.td - Define AMDGPU Combine Rules ----------*- tablegen -*-=//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

include "llvm/Target/GlobalISel/Combine.td"

// TODO: This really belongs after legalization after scalarization.
// TODO: GICombineRules should accept subtarget predicates

def fmin_fmax_legacy_matchdata : GIDefMatchData<"FMinFMaxLegacyInfo">;

def fcmp_select_to_fmin_fmax_legacy : GICombineRule<
  (defs root:$select, fmin_fmax_legacy_matchdata:$matchinfo),
  (match (wip_match_opcode G_SELECT):$select,
         [{ return matchFMinFMaxLegacy(*${select}, MRI, *MF, ${matchinfo}); }]),
  (apply [{ applySelectFCmpToFMinToFMaxLegacy(*${select}, ${matchinfo}); }])>;


def uchar_to_float : GICombineRule<
  (defs root:$itofp),
  (match (wip_match_opcode G_UITOFP, G_SITOFP):$itofp,
         [{ return matchUCharToFloat(*${itofp}, MRI, *MF, Helper); }]),
  (apply [{ applyUCharToFloat(*${itofp}); }])>;

def cvt_f32_ubyteN_matchdata : GIDefMatchData<"CvtF32UByteMatchInfo">;

def cvt_f32_ubyteN : GICombineRule<
  (defs root:$cvt_f32_ubyteN, cvt_f32_ubyteN_matchdata:$matchinfo),
  (match (wip_match_opcode G_AMDGPU_CVT_F32_UBYTE0,
                           G_AMDGPU_CVT_F32_UBYTE1,
                           G_AMDGPU_CVT_F32_UBYTE2,
                           G_AMDGPU_CVT_F32_UBYTE3):$cvt_f32_ubyteN,
         [{ return matchCvtF32UByteN(*${cvt_f32_ubyteN}, MRI, *MF, ${matchinfo}); }]),
  (apply [{ applyCvtF32UByteN(*${cvt_f32_ubyteN}, ${matchinfo}); }])>;

// Combines which should only apply on SI/VI
def gfx6gfx7_combines : GICombineGroup<[fcmp_select_to_fmin_fmax_legacy]>;


def AMDGPUPreLegalizerCombinerHelper: GICombinerHelper<
  "AMDGPUGenPreLegalizerCombinerHelper", [all_combines,
                                          elide_br_by_inverting_cond]> {
  let DisableRuleOption = "amdgpuprelegalizercombiner-disable-rule";
}


// FIXME: combines_for_extload can introduce illegal extloads which
// aren't re-legalized.
// FIXME: Is there a way to remove a single item from all_combines?
def all_combines_minus_extload : GICombineGroup<[trivial_combines,
  ptr_add_immed_chain, combine_indexed_load_store, undef_combines,
  identity_combines]
>;

def AMDGPUPostLegalizerCombinerHelper: GICombinerHelper<
  "AMDGPUGenPostLegalizerCombinerHelper",
  [all_combines_minus_extload, gfx6gfx7_combines,
   uchar_to_float, cvt_f32_ubyteN]> {
  let DisableRuleOption = "amdgpupostlegalizercombiner-disable-rule";
}