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 242e8d3d50d8ac5d0dd6541771f6f02bd54e1102..b0207820ba33985990894405b1d6f03e74d4a390 100644 (file)
--- 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;