Mesa (master): v3d: Emit a simpler negate for the iabs implementation.

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Module: Mesa
Branch: master
Commit: 0bba9c8489726fa7ddb855f5ad68b1934dd0312b
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=0bba9c8489726fa7ddb855f5ad68b1934dd0312b

Author: Eric Anholt <eric at anholt.net>
Date:   Mon Feb 18 18:13:09 2019 -0800

v3d: Emit a simpler negate for the iabs implementation.

One program affected in my shader-db.

instructions in affected programs: 110 -> 108 (-1.82%)

---

 src/broadcom/compiler/nir_to_vir.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/broadcom/compiler/nir_to_vir.c b/src/broadcom/compiler/nir_to_vir.c
index dc65e379b7f..4a0fd7d20e7 100644
--- a/src/broadcom/compiler/nir_to_vir.c
+++ b/src/broadcom/compiler/nir_to_vir.c
@@ -1027,8 +1027,7 @@ ntq_emit_alu(struct v3d_compile *c, nir_alu_instr *instr)
         }
 
         case nir_op_iabs:
-                result = vir_MAX(c, src[0],
-                                vir_SUB(c, vir_uniform_ui(c, 0), src[0]));
+                result = vir_MAX(c, src[0], vir_NEG(c, src[0]));
                 break;
 
         case nir_op_fddx: