aco: improve readfirstlane after uniform ssbo loads on GFX7

pipeline-db changes for GFX7:

80310 shaders in 40472 tests
Totals:
SGPRS: 3655900 -> 3643916 (-0.33 %)
VGPRS: 2678324 -> 2686324 (0.30 %)
Spilled SGPRs: 1730 -> 1634 (-5.55 %)
Spilled VGPRs: 14 -> 21 (50.00 %)
Scratch size: 15540 -> 15536 (-0.03 %) dwords per thread
Code Size: 136106120 -> 135457616 (-0.48 %) bytes
LDS: 1259 -> 1259 (0.00 %) blocks
Max Waves: 601014 -> 600206 (-0.13 %)

Totals from affected shaders:
SGPRS: 307832 -> 295848 (-3.89 %)
VGPRS: 267864 -> 275864 (2.99 %)
Spilled SGPRs: 770 -> 674 (-12.47 %)
Spilled VGPRs: 14 -> 21 (50.00 %)
Scratch size: 16 -> 12 (-25.00 %) dwords per thread
Code Size: 22007488 -> 21358984 (-2.95 %) bytes
LDS: 65 -> 65 (0.00 %) blocks
Max Waves: 28668 -> 27860 (-2.82 %)

Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>

diff --git a/src/amd/compiler/aco_instruction_selection.cpp b/src/amd/compiler/aco_instruction_selection.cpp
index 1cff595659c6b316916bf7105ae5dbe1b183a433..b92d7c0eb5f970fb1e8e7b5abb999b916f15b44e 100644 (file)
--- a/src/amd/compiler/aco_instruction_selection.cpp
+++ b/src/amd/compiler/aco_instruction_selection.cpp
@@ -3447,10 +3447,11 @@ void load_buffer(isel_context *ctx, unsigned num_components, Temp dst,
          Temp vec = bld.tmp(RegType::vgpr, dst.size());
          instr->definitions[0] = Definition(vec);
          bld.insert(std::move(instr));
-         bld.pseudo(aco_opcode::p_as_uniform, Definition(dst), vec);
+         expand_vector(ctx, vec, dst, num_components, (1 << num_components) - 1);
       } else {
          instr->definitions[0] = Definition(dst);
          bld.insert(std::move(instr));
+         emit_split_vector(ctx, dst, num_components);
       }
    } else {
       switch (num_bytes) {
@@ -3506,9 +3507,8 @@ void load_buffer(isel_context *ctx, unsigned num_components, Temp dst,
       } else {
          bld.insert(std::move(load));
       }
-
+      emit_split_vector(ctx, dst, num_components);
    }
-   emit_split_vector(ctx, dst, num_components);
 }
 
 void visit_load_ubo(isel_context *ctx, nir_intrinsic_instr *instr)