Mesa (main): aco/ra: Optimize some SOP2 instructions with literal to SOPK.

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Module: Mesa
Branch: main
Commit: e06773281b3ff7fff86a50e3d2ec4a58b3e035cb
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=e06773281b3ff7fff86a50e3d2ec4a58b3e035cb

Author: Georg Lehmann <dadschoorse at gmail.com>
Date:   Sun Apr 17 13:17:20 2022 +0200

aco/ra: Optimize some SOP2 instructions with literal to SOPK.

Signed-off-by: Georg Lehmann <dadschoorse at gmail.com>
Reviewed-by: Daniel Schürmann <daniel at schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15999>

---

 src/amd/compiler/aco_register_allocation.cpp | 61 +++++++++++++++++++++++++++-
 1 file changed, 60 insertions(+), 1 deletion(-)

diff --git a/src/amd/compiler/aco_register_allocation.cpp b/src/amd/compiler/aco_register_allocation.cpp
index 32ddca431b0..c1cc2d917c5 100644
--- a/src/amd/compiler/aco_register_allocation.cpp
+++ b/src/amd/compiler/aco_register_allocation.cpp
@@ -2592,12 +2592,70 @@ optimize_encoding_vop2(Program* program, ra_ctx& ctx, RegisterFile& register_fil
    }
 }
 
+void
+optimize_encoding_sopk(Program* program, ra_ctx& ctx, RegisterFile& register_file,
+                       aco_ptr<Instruction>& instr)
+{
+   /* try to optimize sop2 with literal source to sopk */
+   if (instr->opcode != aco_opcode::s_add_i32 && instr->opcode != aco_opcode::s_mul_i32 &&
+       instr->opcode != aco_opcode::s_cselect_b32)
+      return;
+
+   uint32_t literal_idx = 0;
+
+   if (instr->opcode != aco_opcode::s_cselect_b32 && instr->operands[1].isLiteral())
+      literal_idx = 1;
+
+   if (!instr->operands[!literal_idx].isTemp() ||
+       !instr->operands[!literal_idx].isKillBeforeDef() ||
+       instr->operands[!literal_idx].getTemp().type() != RegType::sgpr ||
+       instr->operands[!literal_idx].physReg() >= 128)
+      return;
+
+   if (!instr->operands[literal_idx].isLiteral())
+      return;
+
+   const uint32_t i16_mask = 0xffff8000u;
+   uint32_t value = instr->operands[literal_idx].constantValue();
+   if ((value & i16_mask) && (value & i16_mask) != i16_mask)
+      return;
+
+   unsigned def_id = instr->definitions[0].tempId();
+   if (ctx.assignments[def_id].affinity) {
+      assignment& affinity = ctx.assignments[ctx.assignments[def_id].affinity];
+      if (affinity.assigned && affinity.reg != instr->operands[!literal_idx].physReg() &&
+          !register_file.test(affinity.reg, instr->operands[!literal_idx].bytes()))
+         return;
+   }
+
+   static_assert(sizeof(SOPK_instruction) <= sizeof(SOP2_instruction),
+                 "Invalid direct instruction cast.");
+   instr->format = Format::SOPK;
+   SOPK_instruction* instr_sopk = &instr->sopk();
+
+   instr_sopk->imm = instr_sopk->operands[literal_idx].constantValue() & 0xffff;
+   if (literal_idx == 0)
+      std::swap(instr_sopk->operands[0], instr_sopk->operands[1]);
+   if (instr_sopk->operands.size() > 2)
+      std::swap(instr_sopk->operands[1], instr_sopk->operands[2]);
+   instr_sopk->operands.pop_back();
+
+   switch (instr_sopk->opcode) {
+   case aco_opcode::s_add_i32: instr_sopk->opcode = aco_opcode::s_addk_i32; break;
+   case aco_opcode::s_mul_i32: instr_sopk->opcode = aco_opcode::s_mulk_i32; break;
+   case aco_opcode::s_cselect_b32: instr_sopk->opcode = aco_opcode::s_cmovk_i32; break;
+   default: unreachable("illegal instruction");
+   }
+}
+
 void
 optimize_encoding(Program* program, ra_ctx& ctx, RegisterFile& register_file,
                   aco_ptr<Instruction>& instr)
 {
    if (instr->isVALU())
       optimize_encoding_vop2(program, ctx, register_file, instr);
+   if (instr->isSALU())
+      optimize_encoding_sopk(program, ctx, register_file, instr);
 }
 
 } /* end namespace */
@@ -2744,7 +2802,8 @@ register_allocation(Program* program, std::vector<IDSet>& live_out_per_block, ra
                    instr->operands[2].regClass() == v1);
             instr->definitions[0].setFixed(instr->operands[2].physReg());
          } else if (instr->opcode == aco_opcode::s_addk_i32 ||
-                    instr->opcode == aco_opcode::s_mulk_i32) {
+                    instr->opcode == aco_opcode::s_mulk_i32 ||
+                    instr->opcode == aco_opcode::s_cmovk_i32) {
             assert(instr->definitions[0].bytes() == instr->operands[0].bytes());
             instr->definitions[0].setFixed(instr->operands[0].physReg());
          } else if (instr->isMUBUF() && instr->definitions.size() == 1 &&