From: Roland Scheidegger <sroland@vmware.com>
Date: Fri, 8 Oct 2010 19:08:49 +0000 (+0200)
Subject: gallivm: avoid unnecessary URem in linear wrap repeat case
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=2cc6da85d6e60e80d0b5b86fe42f8f82073b5d51;p=mesa.git

gallivm: avoid unnecessary URem in linear wrap repeat case

Haven't looked at what code this exactly generates but URem can't be fast.
Instead of using two URem only use one and replace the second one with
select/add (this is what the corresponding aos code already does).
---

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
index 242e8d3d50d..b0207820ba3 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
@@ -251,19 +251,23 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld,
       coord = lp_build_sub(coord_bld, coord, half);
       /* convert to int, compute lerp weight */
       lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);
-      coord1 = lp_build_add(uint_coord_bld, coord0, uint_coord_bld->one);
       /* repeat wrap */
       if (is_pot) {
+         coord1 = lp_build_add(uint_coord_bld, coord0, uint_coord_bld->one);
          coord0 = LLVMBuildAnd(bld->builder, coord0, length_minus_one, "");
          coord1 = LLVMBuildAnd(bld->builder, coord1, length_minus_one, "");
       }
       else {
          /* Add a bias to the texcoord to handle negative coords */
          LLVMValueRef bias = lp_build_mul_imm(uint_coord_bld, length, 1024);
+         LLVMValueRef mask;
          coord0 = LLVMBuildAdd(bld->builder, coord0, bias, "");
-         coord1 = LLVMBuildAdd(bld->builder, coord1, bias, "");
          coord0 = LLVMBuildURem(bld->builder, coord0, length, "");
-         coord1 = LLVMBuildURem(bld->builder, coord1, length, "");
+         mask = lp_build_compare(bld->builder, int_coord_bld->type,
+                                 PIPE_FUNC_NOTEQUAL, coord0, length_minus_one);
+         coord1 = LLVMBuildAnd(bld->builder,
+                              lp_build_add(uint_coord_bld, coord0, uint_coord_bld->one),
+                              mask, "");
       }
       break;