I found a shader in Tales of Maj'Eyal that contains:
if ssa_21 {
block block_1:
/* preds: block_0 */
...instructions that prevent the select peephole...
vec1 32 ssa_23 = imov ssa_4
vec1 32 ssa_24 = imov ssa_4.y
vec1 32 ssa_25 = imov ssa_4.z
/* succs: block_3 */
} else {
block block_2:
/* preds: block_0 */
vec1 32 ssa_26 = imov ssa_4
vec1 32 ssa_27 = imov ssa_4.y
vec1 32 ssa_28 = imov ssa_4.z
/* succs: block_3 */
}
block block_3:
/* preds: block_1 block_2 */
vec1 32 ssa_29 = phi block_1: ssa_23, block_2: ssa_26
vec1 32 ssa_30 = phi block_1: ssa_24, block_2: ssa_27
vec1 32 ssa_31 = phi block_1: ssa_25, block_2: ssa_28
Here, copy propagation will bail because phis cannot perform swizzles,
and CSE won't do anything because there is no dominance relationship
between the imovs. By making nir_opt_remove_phis handle identical moves,
we can eliminate the phis and rewrite everything to use ssa_4 directly,
so all the moves become dead and get eliminated.
I don't think we need to check "exact" - just the alu sources.
Presumably phi sources should match in their exactness.
On Broadwell:
total instructions in shared programs: 11639872 -> 11638535 (-0.01%)
instructions in affected programs: 134222 -> 132885 (-1.00%)
helped: 338
HURT: 0
v2: Fix return value to be NULL, not false (caught by Iago).
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
This matches the "foreach x in container" pattern found in many other
programming languages. Generated by the following regular expression:
s/nir_foreach_function(\([^,]*\),\s*\([^,]*\))/nir_foreach_function(\2, \1)/
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
This matches the "foreach x in container" pattern found in many other
programming languages. Generated by the following regular expression:
s/nir_foreach_phi_src(\([^,]*\),\s*\([^,]*\))/nir_foreach_phi_src(\2, \1)/
and a similar expression for nir_foreach_phi_src_safe.
Reviewed-by: Eduardo Lima Mitev <elima@igalia.com>
This matches the "foreach x in container" pattern found in many other
programming languages. Generated by the following regular expression:
s/nir_foreach_instr(\([^,]*\),\s*\([^,]*\))/nir_foreach_instr(\2, \1)/
and similar expressions for nir_foreach_instr_safe etc.
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Kenneth Graunke
Jason Ekstrand
Connor Abbott
Emil Velikov