gallivm: Combined ifloor & fract helper.

The only way to ensure we don't do redundant FP <-> SI conversions.

4 files changed, 65 insertions, 28 deletions

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_arit.c b/src/gallium/auxiliary/gallivm/lp_bld_arit.c
index 15b7441018..64c468c14d 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_arit.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_arit.c
@@ -1359,6 +1359,48 @@ lp_build_iceil(struct lp_build_context *bld,
 }
 
 
+/**
+ * Combined ifloor() & fract().
+ *
+ * Preferred to calling the functions separately, as it will ensure that the
+ * stratergy (floor() vs ifloor()) that results in less redundant work is used.
+ */
+void
+lp_build_ifloor_fract(struct lp_build_context *bld,
+                      LLVMValueRef a,
+                      LLVMValueRef *out_ipart,
+                      LLVMValueRef *out_fpart)
+{
+
+
+   const struct lp_type type = bld->type;
+   LLVMValueRef ipart;
+
+   assert(type.floating);
+   assert(lp_check_value(type, a));
+
+   if (util_cpu_caps.has_sse4_1 &&
+       (type.length == 1 || type.width*type.length == 128)) {
+      /*
+       * floor() is easier.
+       */
+
+      ipart = lp_build_floor(bld, a);
+      *out_fpart = LLVMBuildFSub(bld->builder, a, ipart, "fpart");
+      *out_ipart = LLVMBuildFPToSI(bld->builder, ipart, bld->int_vec_type, "ipart");
+   }
+   else {
+      /*
+       * ifloor() is easier.
+       */
+
+      *out_ipart = lp_build_ifloor(bld, a);
+      ipart = LLVMBuildSIToFP(bld->builder, *out_ipart, bld->vec_type, "ipart");
+      *out_fpart = LLVMBuildFSub(bld->builder, a, ipart, "fpart");
+   }
+}
+
+
 LLVMValueRef
 lp_build_sqrt(struct lp_build_context *bld,
               LLVMValueRef a)
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_arit.h b/src/gallium/auxiliary/gallivm/lp_bld_arit.h
index f36197479f..8424384f8f 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_arit.h
+++ b/src/gallium/auxiliary/gallivm/lp_bld_arit.h
@@ -171,6 +171,12 @@ LLVMValueRef
 lp_build_itrunc(struct lp_build_context *bld,
                 LLVMValueRef a);
 
+void
+lp_build_ifloor_fract(struct lp_build_context *bld,
+                      LLVMValueRef a,
+                      LLVMValueRef *out_ipart,
+                      LLVMValueRef *out_fpart);
+
 LLVMValueRef
 lp_build_sqrt(struct lp_build_context *bld,
               LLVMValueRef a);
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample.c b/src/gallium/auxiliary/gallivm/lp_bld_sample.c
index 9dee653eee..acd99741f1 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample.c
@@ -319,7 +319,7 @@ lp_build_linear_mip_levels(struct lp_build_sample_context *bld,
                                                bld->builder, unit);
 
    /* convert float lod to integer */
-   level = lp_build_ifloor(float_bld, lod);
+   lp_build_ifloor_fract(float_bld, lod, &level, weight_out);
 
    /* compute level 0 and clamp to legal range of levels */
    *level0_out = lp_build_clamp(int_bld, level,
@@ -330,8 +330,6 @@ lp_build_linear_mip_levels(struct lp_build_sample_context *bld,
    *level1_out = lp_build_clamp(int_bld, level,
                                 int_bld->zero,
                                 last_level);
-
-   *weight_out = lp_build_fract(float_bld, lod);
 }
 
 
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
index 36a77d3aff..d464147371 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
@@ -253,11 +253,9 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld,
       /* mul by size and subtract 0.5 */
       coord = lp_build_mul(coord_bld, coord, length_f);
       coord = lp_build_sub(coord_bld, coord, half);
-      /* convert to int */
-      coord0 = lp_build_ifloor(coord_bld, coord);
+      /* 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);
-      /* compute lerp weight */
-      weight = lp_build_fract(coord_bld, coord);
       /* repeat wrap */
       if (is_pot) {
          coord0 = LLVMBuildAnd(bld->builder, coord0, length_minus_one, "");
@@ -284,8 +282,8 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld,
 
       coord = lp_build_sub(coord_bld, coord, half);
 
-      weight = lp_build_fract(coord_bld, coord);
-      coord0 = lp_build_ifloor(coord_bld, coord);
+      /* convert to int, compute lerp weight */
+      lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);
       coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
       break;
 
@@ -304,10 +302,8 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld,
          max = lp_build_sub(coord_bld, length_f, min);
          coord = lp_build_clamp(coord_bld, coord, min, max);
       }
-      /* compute lerp weight */
-      weight = lp_build_fract(coord_bld, coord);
-      /* coord0 = floor(coord); */
-      coord0 = lp_build_ifloor(coord_bld, coord);
+      /* convert to int, compute lerp weight */
+      lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);
       coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
       /* coord0 = max(coord0, 0) */
       coord0 = lp_build_max(int_coord_bld, coord0, int_coord_bld->zero);
@@ -327,10 +323,8 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld,
          max = lp_build_sub(coord_bld, length_f, min);
          coord = lp_build_clamp(coord_bld, coord, min, max);
          coord = lp_build_sub(coord_bld, coord, half);
-         /* compute lerp weight */
-         weight = lp_build_fract(coord_bld, coord);
-         /* convert to int */
-         coord0 = lp_build_ifloor(coord_bld, coord);
+         /* convert to int, compute lerp weight */
+         lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);
          coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
       }
       break;
@@ -343,11 +337,8 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld,
       coord = lp_build_mul(coord_bld, coord, length_f);
       coord = lp_build_sub(coord_bld, coord, half);
 
-      /* compute lerp weight */
-      weight = lp_build_fract(coord_bld, coord);
-
-      /* convert to int coords */
-      coord0 = lp_build_ifloor(coord_bld, coord);
+      /* convert to int, compute lerp weight */
+      lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);
       coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
 
       /* coord0 = max(coord0, 0) */
@@ -369,8 +360,8 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld,
 
       coord = lp_build_sub(coord_bld, coord, half);
 
-      weight = lp_build_fract(coord_bld, coord);
-      coord0 = lp_build_ifloor(coord_bld, coord);
+      /* convert to int, compute lerp weight */
+      lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);
       coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
       break;
 
@@ -392,8 +383,8 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld,
 
          coord = lp_build_sub(coord_bld, coord, half);
 
-         weight = lp_build_fract(coord_bld, coord);
-         coord0 = lp_build_ifloor(coord_bld, coord);
+         /* convert to int, compute lerp weight */
+         lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);
          coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
       }
       break;
@@ -416,8 +407,8 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld,
 
          coord = lp_build_sub(coord_bld, coord, half);
 
-         weight = lp_build_fract(coord_bld, coord);
-         coord0 = lp_build_ifloor(coord_bld, coord);
+         /* convert to int, compute lerp weight */
+         lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);
          coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
       }
       break;