diff options
| -rw-r--r-- | src/compiler/nir/nir_opt_loop_unroll.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/src/compiler/nir/nir_opt_loop_unroll.c b/src/compiler/nir/nir_opt_loop_unroll.c index 37cbced43dd..79d04f978bc 100644 --- a/src/compiler/nir/nir_opt_loop_unroll.c +++ b/src/compiler/nir/nir_opt_loop_unroll.c @@ -26,6 +26,16 @@ #include "nir_control_flow.h" #include "nir_loop_analyze.h" + +/* This limit is chosen fairly arbitrarily. GLSL IR max iteration is 32 + * instructions. (Multiply counting nodes and magic number 5.) But there is + * no 1:1 mapping between GLSL IR and NIR so 25 was picked because it seemed + * to give about the same results. Around 5 instructions per node. But some + * loops that would unroll with GLSL IR fail to unroll if we set this to 25 so + * we set it to 26. + */ +#define LOOP_UNROLL_LIMIT 26 + /* Prepare this loop for unrolling by first converting to lcssa and then * converting the phis from the loops first block and the block that follows * the loop into regs. Partially converting out of SSA allows us to unroll @@ -460,7 +470,7 @@ is_loop_small_enough_to_unroll(nir_shader *shader, nir_loop_info *li) return true; bool loop_not_too_large = - li->num_instructions * li->trip_count <= max_iter * 26; + li->num_instructions * li->trip_count <= max_iter * LOOP_UNROLL_LIMIT; return loop_not_too_large; } |