nir: Add posibility to not lower to source mod 'abs' for ops with three sources

This is useful for r600 since there the abs source modifier is not supported
for ops with three sources

v2: Use correct logic to enable lowering to abs source mod (Eric Anhold)

Signed-off-by: Gert Wollny <gw.fossdev@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>

diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index 3403f841939cc552553952bdc8fb9fe92a26fe84..ac574f903f060aefd63747c64a8b917ce1e446de 100644 (file)
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -3205,7 +3205,8 @@ bool nir_lower_atomics_to_ssbo(nir_shader *shader, unsigned ssbo_offset);
 typedef enum  {
    nir_lower_int_source_mods = 1 << 0,
    nir_lower_float_source_mods = 1 << 1,
-   nir_lower_all_source_mods = (1 << 2) - 1
+   nir_lower_triop_abs = 1 << 2,
+   nir_lower_all_source_mods = (1 << 3) - 1
 } nir_lower_to_source_mods_flags;
 
 

diff --git a/src/compiler/nir/nir_lower_to_source_mods.c b/src/compiler/nir/nir_lower_to_source_mods.c
index 657bf8a3d71ea5afe99e1d0064fc0729ca65e1e9..3ca53c34afc595a42944cf975c7a8adc284ef354 100644 (file)
--- a/src/compiler/nir/nir_lower_to_source_mods.c
+++ b/src/compiler/nir/nir_lower_to_source_mods.c
@@ -45,6 +45,9 @@ nir_lower_to_source_mods_block(nir_block *block,
 
       nir_alu_instr *alu = nir_instr_as_alu(instr);
 
+      bool lower_abs = (nir_op_infos[alu->op].num_inputs < 3) ||
+            (options & nir_lower_triop_abs);
+
       for (unsigned i = 0; i < nir_op_infos[alu->op].num_inputs; i++) {
          if (!alu->src[i].src.is_ssa)
             continue;
@@ -81,6 +84,9 @@ nir_lower_to_source_mods_block(nir_block *block,
          if (!parent->src[0].src.is_ssa)
             continue;
 
+         if (!lower_abs && parent->src[0].abs)
+            continue;
+
          nir_instr_rewrite_src(instr, &alu->src[i].src, parent->src[0].src);
          if (alu->src[i].abs) {
             /* abs trumps both neg and abs, do nothing */