lp_build_linear_mip_levels(struct lp_build_sample_context *bld,
unsigned unit,
LLVMValueRef lod_ipart,
+ LLVMValueRef *lod_fpart_inout,
LLVMValueRef *level0_out,
LLVMValueRef *level1_out)
{
+ LLVMBuilderRef builder = bld->builder;
struct lp_build_context *int_bld = &bld->int_bld;
- LLVMValueRef last_level, level;
+ struct lp_build_context *float_bld = &bld->float_bld;
+ LLVMValueRef last_level;
+ LLVMValueRef clamp_min;
+ LLVMValueRef clamp_max;
+
+ *level0_out = lod_ipart;
+ *level1_out = lp_build_add(int_bld, lod_ipart, int_bld->one);
last_level = bld->dynamic_state->last_level(bld->dynamic_state,
bld->builder, unit);
- /* convert float lod to integer */
- level = lod_ipart;
+ /*
+ * Clamp both lod_ipart and lod_ipart + 1 to [0, last_level], with the
+ * minimum number of comparisons, and zeroing lod_fpart in the extreme
+ * ends in the process.
+ */
+
+ /* lod_ipart < 0 */
+ clamp_min = LLVMBuildICmp(builder, LLVMIntSLT,
+ lod_ipart, int_bld->zero,
+ "clamp_lod_to_zero");
+
+ *level0_out = LLVMBuildSelect(builder, clamp_min,
+ int_bld->zero, *level0_out, "");
+
+ *level1_out = LLVMBuildSelect(builder, clamp_min,
+ int_bld->zero, *level1_out, "");
+
+ *lod_fpart_inout = LLVMBuildSelect(builder, clamp_min,
+ float_bld->zero, *lod_fpart_inout, "");
+
+ /* lod_ipart >= last_level */
+ clamp_max = LLVMBuildICmp(builder, LLVMIntSGE,
+ lod_ipart, last_level,
+ "clamp_lod_to_last");
+
+ *level0_out = LLVMBuildSelect(builder, clamp_max,
+ int_bld->zero, *level0_out, "");
+
+ *level1_out = LLVMBuildSelect(builder, clamp_max,
+ int_bld->zero, *level1_out, "");
+
+ *lod_fpart_inout = LLVMBuildSelect(builder, clamp_max,
+ float_bld->zero, *lod_fpart_inout, "");
- /* compute level 0 and clamp to legal range of levels */
- *level0_out = lp_build_clamp(int_bld, level,
- int_bld->zero,
- last_level);
- /* compute level 1 and clamp to legal range of levels */
- level = lp_build_add(int_bld, level, int_bld->one);
- *level1_out = lp_build_clamp(int_bld, level,
- int_bld->zero,
- last_level);
+ lp_build_name(*level0_out, "sampler%u_miplevel0", unit);
+ lp_build_name(*level1_out, "sampler%u_miplevel1", unit);
+ lp_build_name(*lod_fpart_inout, "sampler%u_mipweight", unit);
}