1 /**************************************************************************
2  *
3  * Copyright 2009 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 above copyright notice and this permission notice (including the
15  * next paragraph) shall be included in all copies or substantial portions
16  * of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25  *
26  **************************************************************************/
27 
28 /**
29  * LLVM control flow build helpers.
30  *
31  * @author Jose Fonseca <jfonseca@vmware.com>
32  */
33 
34 #ifndef LP_BLD_FLOW_H
35 #define LP_BLD_FLOW_H
36 
37 
38 #include "gallivm/lp_bld.h"
39 
40 
41 struct lp_type;
42 
43 
44 /**
45  * Early exit. Useful to skip to the end of a function or block when
46  * the execution mask becomes zero or when there is an error condition.
47  */
48 struct lp_build_skip_context
49 {
50    struct gallivm_state *gallivm;
51 
52    /** Block to skip to */
53    LLVMBasicBlockRef block;
54 };
55 
56 void
57 lp_build_flow_skip_begin(struct lp_build_skip_context *ctx,
58                          struct gallivm_state *gallivm);
59 
60 void
61 lp_build_flow_skip_cond_break(struct lp_build_skip_context *ctx,
62                               LLVMValueRef cond);
63 
64 void
65 lp_build_flow_skip_end(struct lp_build_skip_context *ctx);
66 
67 
68 struct lp_build_mask_context
69 {
70    struct lp_build_skip_context skip;
71 
72    LLVMTypeRef reg_type;
73 
74    LLVMValueRef var;
75 };
76 
77 
78 void
79 lp_build_mask_begin(struct lp_build_mask_context *mask,
80                     struct gallivm_state *gallivm,
81                     struct lp_type type,
82                     LLVMValueRef value);
83 
84 LLVMValueRef
85 lp_build_mask_value(struct lp_build_mask_context *mask);
86 
87 /**
88  * Bitwise AND the mask with the given value, if a previous mask was set.
89  */
90 void
91 lp_build_mask_update(struct lp_build_mask_context *mask,
92                      LLVMValueRef value);
93 
94 void
95 lp_build_mask_check(struct lp_build_mask_context *mask);
96 
97 LLVMValueRef
98 lp_build_mask_end(struct lp_build_mask_context *mask);
99 
100 
101 /**
102  * LLVM's IR doesn't represent for-loops directly. Furthermore it
103  * it requires creating code blocks, branches, phi variables, so it
104  * requires a fair amount of code.
105  *
106  * @sa http://www.llvm.org/docs/tutorial/LangImpl5.html#for
107  */
108 struct lp_build_loop_state
109 {
110    LLVMBasicBlockRef block;
111    LLVMValueRef counter_var;
112    LLVMValueRef counter;
113    struct gallivm_state *gallivm;
114 };
115 
116 
117 void
118 lp_build_loop_begin(struct lp_build_loop_state *state,
119                     struct gallivm_state *gallivm,
120                     LLVMValueRef start);
121 
122 void
123 lp_build_loop_end(struct lp_build_loop_state *state,
124                   LLVMValueRef end,
125                   LLVMValueRef step);
126 
127 void
128 lp_build_loop_end_cond(struct lp_build_loop_state *state,
129                        LLVMValueRef end,
130                        LLVMValueRef step,
131                        LLVMIntPredicate cond);
132 
133 
134 /**
135  * Implementation of simple C-style for loops
136  */
137 struct lp_build_for_loop_state
138 {
139    LLVMBasicBlockRef begin;
140    LLVMBasicBlockRef body;
141    LLVMBasicBlockRef exit;
142    LLVMValueRef counter_var;
143    LLVMValueRef counter;
144    LLVMValueRef step;
145    LLVMIntPredicate cond;
146    LLVMValueRef end;
147    struct gallivm_state *gallivm;
148 };
149 
150 void
151 lp_build_for_loop_begin(struct lp_build_for_loop_state *state,
152                         struct gallivm_state *gallivm,
153                         LLVMValueRef start,
154                         LLVMIntPredicate llvm_cond,
155                         LLVMValueRef end,
156                         LLVMValueRef step);
157 
158 void
159 lp_build_for_loop_end(struct lp_build_for_loop_state *state);
160 
161 
162 /**
163  * if/else/endif.
164  */
165 struct lp_build_if_state
166 {
167    struct gallivm_state *gallivm;
168    LLVMValueRef condition;
169    LLVMBasicBlockRef entry_block;
170    LLVMBasicBlockRef true_block;
171    LLVMBasicBlockRef false_block;
172    LLVMBasicBlockRef merge_block;
173 };
174 
175 
176 void
177 lp_build_if(struct lp_build_if_state *ctx,
178             struct gallivm_state *gallivm,
179             LLVMValueRef condition);
180 
181 void
182 lp_build_else(struct lp_build_if_state *ctx);
183 
184 void
185 lp_build_endif(struct lp_build_if_state *ctx);
186 
187 LLVMBasicBlockRef
188 lp_build_insert_new_block(struct gallivm_state *gallivm, const char *name);
189 
190 LLVMValueRef
191 lp_build_alloca(struct gallivm_state *gallivm,
192                 LLVMTypeRef type,
193                 const char *name);
194 
195 LLVMValueRef
196 lp_build_array_alloca(struct gallivm_state *gallivm,
197                       LLVMTypeRef type,
198                       LLVMValueRef count,
199                       const char *name);
200 
201 #endif /* !LP_BLD_FLOW_H */
202