From: Jason Ekstrand <jason.ekstrand@intel.com>
Date: Wed, 16 Mar 2016 23:06:10 +0000 (-0700)
Subject: i965: Remove the RCP+RSQ algebraic optimizations
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=01425c45b32fa7f323515b05697c6cc0d245ad32;p=mesa.git

i965: Remove the RCP+RSQ algebraic optimizations

NIR already has this optimization and it can do much better than the little
peephole in the backend.

No shader-db change on Haswell or Broadwell.

Reviewed-by: Matt Turner <mattst88@gmail.com>
---

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index eaff9535c22..1a6a229e444 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -2274,17 +2274,6 @@ fs_visitor::opt_algebraic()
             progress = true;
          }
          break;
-      case SHADER_OPCODE_RCP: {
-         fs_inst *prev = (fs_inst *)inst->prev;
-         if (prev->opcode == SHADER_OPCODE_SQRT) {
-            if (inst->src[0].equals(prev->dst)) {
-               inst->opcode = SHADER_OPCODE_RSQ;
-               inst->src[0] = prev->src[0];
-               progress = true;
-            }
-         }
-         break;
-      }
       case SHADER_OPCODE_BROADCAST:
          if (is_uniform(inst->src[0])) {
             inst->opcode = BRW_OPCODE_MOV;
diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp
index baf72a25c42..b9cf3f657a1 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp
@@ -699,17 +699,6 @@ vec4_visitor::opt_algebraic()
             break;
          }
          break;
-      case SHADER_OPCODE_RCP: {
-         vec4_instruction *prev = (vec4_instruction *)inst->prev;
-         if (prev->opcode == SHADER_OPCODE_SQRT) {
-            if (inst->src[0].equals(src_reg(prev->dst))) {
-               inst->opcode = SHADER_OPCODE_RSQ;
-               inst->src[0] = prev->src[0];
-               progress = true;
-            }
-         }
-         break;
-      }
       case SHADER_OPCODE_BROADCAST:
          if (is_uniform(inst->src[0]) ||
              inst->src[1].is_zero()) {