1 /**************************************************************************
2 *
3 * Copyright 2010 VMware, Inc.
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
18 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
19 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
20 * USE OR OTHER DEALINGS IN THE SOFTWARE.
21 *
22 * The above copyright notice and this permission notice (including the
23 * next paragraph) shall be included in all copies or substantial portions
24 * of the Software.
25 *
26 **************************************************************************/
27
28
29 #include "util/u_debug.h"
30 #include "lp_bld_debug.h"
31 #include "lp_bld_const.h"
32 #include "lp_bld_format.h"
33 #include "lp_bld_gather.h"
34 #include "lp_bld_init.h"
35
36
37 /**
38 * Get the pointer to one element from scatter positions in memory.
39 *
40 * @sa lp_build_gather()
41 */
42 LLVMValueRef
lp_build_gather_elem_ptr(struct gallivm_state * gallivm,unsigned length,LLVMValueRef base_ptr,LLVMValueRef offsets,unsigned i)43 lp_build_gather_elem_ptr(struct gallivm_state *gallivm,
44 unsigned length,
45 LLVMValueRef base_ptr,
46 LLVMValueRef offsets,
47 unsigned i)
48 {
49 LLVMValueRef offset;
50 LLVMValueRef ptr;
51
52 assert(LLVMTypeOf(base_ptr) == LLVMPointerType(LLVMInt8TypeInContext(gallivm->context), 0));
53
54 if (length == 1) {
55 assert(i == 0);
56 offset = offsets;
57 } else {
58 LLVMValueRef index = lp_build_const_int32(gallivm, i);
59 offset = LLVMBuildExtractElement(gallivm->builder, offsets, index, "");
60 }
61
62 ptr = LLVMBuildGEP(gallivm->builder, base_ptr, &offset, 1, "");
63
64 return ptr;
65 }
66
67
68 /**
69 * Gather one element from scatter positions in memory.
70 *
71 * @sa lp_build_gather()
72 */
73 LLVMValueRef
lp_build_gather_elem(struct gallivm_state * gallivm,unsigned length,unsigned src_width,unsigned dst_width,LLVMValueRef base_ptr,LLVMValueRef offsets,unsigned i)74 lp_build_gather_elem(struct gallivm_state *gallivm,
75 unsigned length,
76 unsigned src_width,
77 unsigned dst_width,
78 LLVMValueRef base_ptr,
79 LLVMValueRef offsets,
80 unsigned i)
81 {
82 LLVMTypeRef src_type = LLVMIntTypeInContext(gallivm->context, src_width);
83 LLVMTypeRef src_ptr_type = LLVMPointerType(src_type, 0);
84 LLVMTypeRef dst_elem_type = LLVMIntTypeInContext(gallivm->context, dst_width);
85 LLVMValueRef ptr;
86 LLVMValueRef res;
87
88 assert(LLVMTypeOf(base_ptr) == LLVMPointerType(LLVMInt8TypeInContext(gallivm->context), 0));
89
90 ptr = lp_build_gather_elem_ptr(gallivm, length, base_ptr, offsets, i);
91 ptr = LLVMBuildBitCast(gallivm->builder, ptr, src_ptr_type, "");
92 res = LLVMBuildLoad(gallivm->builder, ptr, "");
93
94 assert(src_width <= dst_width);
95 if (src_width > dst_width)
96 res = LLVMBuildTrunc(gallivm->builder, res, dst_elem_type, "");
97 if (src_width < dst_width)
98 res = LLVMBuildZExt(gallivm->builder, res, dst_elem_type, "");
99
100 return res;
101 }
102
103
104 /**
105 * Gather elements from scatter positions in memory into a single vector.
106 * Use for fetching texels from a texture.
107 * For SSE, typical values are length=4, src_width=32, dst_width=32.
108 *
109 * @param length length of the offsets
110 * @param src_width src element width in bits
111 * @param dst_width result element width in bits (src will be expanded to fit)
112 * @param base_ptr base pointer, should be a i8 pointer type.
113 * @param offsets vector with offsets
114 */
115 LLVMValueRef
lp_build_gather(struct gallivm_state * gallivm,unsigned length,unsigned src_width,unsigned dst_width,LLVMValueRef base_ptr,LLVMValueRef offsets)116 lp_build_gather(struct gallivm_state *gallivm,
117 unsigned length,
118 unsigned src_width,
119 unsigned dst_width,
120 LLVMValueRef base_ptr,
121 LLVMValueRef offsets)
122 {
123 LLVMValueRef res;
124
125 if (length == 1) {
126 /* Scalar */
127 return lp_build_gather_elem(gallivm, length,
128 src_width, dst_width,
129 base_ptr, offsets, 0);
130 } else {
131 /* Vector */
132
133 LLVMTypeRef dst_elem_type = LLVMIntTypeInContext(gallivm->context, dst_width);
134 LLVMTypeRef dst_vec_type = LLVMVectorType(dst_elem_type, length);
135 unsigned i;
136
137 res = LLVMGetUndef(dst_vec_type);
138 for (i = 0; i < length; ++i) {
139 LLVMValueRef index = lp_build_const_int32(gallivm, i);
140 LLVMValueRef elem;
141 elem = lp_build_gather_elem(gallivm, length,
142 src_width, dst_width,
143 base_ptr, offsets, i);
144 res = LLVMBuildInsertElement(gallivm->builder, res, elem, index, "");
145 }
146 }
147
148 return res;
149 }
150
151 LLVMValueRef
lp_build_gather_values(struct gallivm_state * gallivm,LLVMValueRef * values,unsigned value_count)152 lp_build_gather_values(struct gallivm_state * gallivm,
153 LLVMValueRef * values,
154 unsigned value_count)
155 {
156 LLVMTypeRef vec_type = LLVMVectorType(LLVMTypeOf(values[0]), value_count);
157 LLVMBuilderRef builder = gallivm->builder;
158 LLVMValueRef vec = LLVMGetUndef(vec_type);
159 unsigned i;
160
161 for (i = 0; i < value_count; i++) {
162 LLVMValueRef index = lp_build_const_int32(gallivm, i);
163 vec = LLVMBuildInsertElement(builder, vec, values[i], index, "");
164 }
165 return vec;
166 }
167