[Mesa-dev] [PATCH v4 22/28] i965/vec4: Fix exec size for MOVs {SET, PICK}_{HIGH, LOW}_32BIT.

[Samuel Iglesias Gonsálvez]

From: Matt Turner <mattst88 at gmail.com>

Otherwise for a pack_double_2x32_split opcode, we emit:

   vec1 64 ssa_135 = pack_double_2x32_split ssa_133, ssa_134
mov(8)          g5<1>UD         g5<4>.xUD                       { align16 1Q compacted };
mov(8)          g7<2>UD         g5<4,4,1>UD                     { align1 1Q };
        ERROR: When the destination spans two registers, the source must span two registers
               (exceptions for scalar source and packed-word to packed-dword expansion)
mov(8)          g8<2>UD         g5.4<4,4,1>UD                   { align1 2N };
        ERROR: The offset from the two source registers must be the same
mov(8)          g5<1>UD         g6<4>.xUD                       { align16 1Q compacted };
mov(8)          g7.1<2>UD       g5<4,4,1>UD                     { align1 1Q };
        ERROR: When the destination spans two registers, the source must span two registers
               (exceptions for scalar source and packed-word to packed-dword expansion)
mov(8)          g8.1<2>UD       g5.4<4,4,1>UD                   { align1 2N };
        ERROR: The offset from the two source registers must be the same

The intention was to emit mov(4)s for the instructions that have ERROR
annotations.

See tests/spec/arb_gpu_shader_fp64/execution/vs-isinf-dvec.shader_test
for example.

v2 (Samuel):
- Instead of setting the exec size to a fixed value, don't double it
(Curro).
- Add PICK_{HIGH,LOW}_32BIT to the condition.

Signed-off-by: Samuel Iglesias Gonsálvez <siglesias at igalia.com>
---
 src/intel/compiler/brw_vec4_generator.cpp | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/intel/compiler/brw_vec4_generator.cpp b/src/intel/compiler/brw_vec4_generator.cpp
index eab039093d0..e36c057816f 100644
--- a/src/intel/compiler/brw_vec4_generator.cpp
+++ b/src/intel/compiler/brw_vec4_generator.cpp
@@ -1539,7 +1539,15 @@ generate_code(struct brw_codegen *p,
              inst->src[2].type == BRW_REGISTER_TYPE_DF);
 
       unsigned exec_size = inst->exec_size;
-      if (is_ivb_df && inst->exec_size < 8)
+      /* There are some instructions where the destination is 64-bit
+       * but we retype it to a smaller type. In that case, we cannot
+       * double the exec_size.
+       */
+      if (is_ivb_df && inst->exec_size < 8 &&
+          inst->opcode != VEC4_OPCODE_PICK_LOW_32BIT &&
+          inst->opcode != VEC4_OPCODE_PICK_HIGH_32BIT &&
+          inst->opcode != VEC4_OPCODE_SET_LOW_32BIT &&
+          inst->opcode != VEC4_OPCODE_SET_HIGH_32BIT)
          exec_size *= 2;
 
       brw_set_default_exec_size(p, cvt(exec_size) - 1);
-- 
2.11.0