Mesa (main): aco: Reuse previous -1 result in find_msb to avoid using VOP3.

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Module: Mesa
Branch: main
Commit: d12b5e76331a3ac6067bf21093a0c06a2ba6ca13
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=d12b5e76331a3ac6067bf21093a0c06a2ba6ca13

Author: Georg Lehmann <dadschoorse at gmail.com>
Date:   Fri Dec 31 17:38:25 2021 +0100

aco: Reuse previous -1 result in find_msb to avoid using VOP3.

Totals:
CodeSize: 388934388 -> 388933712 (-0.00%)

Totals from 208 (0.15% of 134913) affected shaders:
CodeSize: 2008016 -> 2007340 (-0.03%)

Signed-off-by: Georg Lehmann <dadschoorse at gmail.com>
Reviewed-by: Rhys Perry <pendingchaos02 at gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16011>

---

 src/amd/compiler/aco_instruction_selection.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/amd/compiler/aco_instruction_selection.cpp b/src/amd/compiler/aco_instruction_selection.cpp
index ac1a53bf5c5..69006733189 100644
--- a/src/amd/compiler/aco_instruction_selection.cpp
+++ b/src/amd/compiler/aco_instruction_selection.cpp
@@ -1743,7 +1743,7 @@ visit_alu_instr(isel_context* ctx, nir_alu_instr* instr)
          Temp msb = bld.tmp(v1);
          Temp carry =
             bld.vsub32(Definition(msb), Operand::c32(31u), Operand(msb_rev), true).def(1).getTemp();
-         bld.vop2_e64(aco_opcode::v_cndmask_b32, Definition(dst), msb, Operand::c32(-1), carry);
+         bld.vop2(aco_opcode::v_cndmask_b32, Definition(dst), msb, msb_rev, carry);
       } else if (src.regClass() == v2) {
          aco_opcode op =
             instr->op == nir_op_ufind_msb ? aco_opcode::v_ffbh_u32 : aco_opcode::v_ffbh_i32;
@@ -1761,7 +1761,7 @@ visit_alu_instr(isel_context* ctx, nir_alu_instr* instr)
          Temp msb = bld.tmp(v1);
          Temp carry =
             bld.vsub32(Definition(msb), Operand::c32(63u), Operand(msb_rev), true).def(1).getTemp();
-         bld.vop2_e64(aco_opcode::v_cndmask_b32, Definition(dst), msb, Operand::c32(-1), carry);
+         bld.vop2(aco_opcode::v_cndmask_b32, Definition(dst), msb, msb_rev, carry);
       } else {
          isel_err(&instr->instr, "Unimplemented NIR instr bit size");
       }