From: Eric Anholt <eric@anholt.net>
Date: Tue, 19 Feb 2019 02:13:09 +0000 (-0800)
Subject: v3d: Emit a simpler negate for the iabs implementation.
X-Git-Tag: upstream/19.3.0~9692
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0bba9c8489726fa7ddb855f5ad68b1934dd0312b;p=platform%2Fupstream%2Fmesa.git

v3d: Emit a simpler negate for the iabs implementation.

One program affected in my shader-db.

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

diff --git a/src/broadcom/compiler/nir_to_vir.c b/src/broadcom/compiler/nir_to_vir.c
index dc65e37..4a0fd7d 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: