Mesa (glsl-continue-return): glsl: implement _slang_gen_while_without_continue()
Brian Paul
brianp at kemper.freedesktop.org
Tue Jun 23 20:06:38 UTC 2009
Module: Mesa
Branch: glsl-continue-return
Commit: 641c6a5c332c1a64aa945854d9dc3320cf98a0c5
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=641c6a5c332c1a64aa945854d9dc3320cf98a0c5
Author: Brian Paul <brianp at vmware.com>
Date: Tue Jun 23 14:05:11 2009 -0600
glsl: implement _slang_gen_while_without_continue()
---
src/mesa/shader/slang/slang_codegen.c | 197 +++++++++++++++++++--------------
1 files changed, 115 insertions(+), 82 deletions(-)
diff --git a/src/mesa/shader/slang/slang_codegen.c b/src/mesa/shader/slang/slang_codegen.c
index 787bdb5..2c43e53 100644
--- a/src/mesa/shader/slang/slang_codegen.c
+++ b/src/mesa/shader/slang/slang_codegen.c
@@ -2411,14 +2411,102 @@ _slang_loop_contains_continue_or_break(const slang_operation *oper)
}
+/**
+ * Replace 'break' and 'continue' statements inside a do and while loops.
+ * This is a recursive helper function used by
+ * _slang_gen_do/while_without_continue().
+ */
+static void
+replace_break_and_cont(slang_assemble_ctx *A, slang_operation *oper)
+{
+ switch (oper->type) {
+ case SLANG_OPER_BREAK:
+ /* replace 'break' with "_notBreakFlag = false; break" */
+ {
+ slang_operation *block = oper;
+ block->type = SLANG_OPER_BLOCK_NEW_SCOPE;
+ slang_operation_add_children(block, 2);
+ {
+ slang_operation *assign = slang_oper_child(block, 0);
+ assign->type = SLANG_OPER_ASSIGN;
+ slang_operation_add_children(assign, 2);
+ {
+ slang_operation *lhs = slang_oper_child(assign, 0);
+ slang_operation_identifier(lhs, A, "_notBreakFlag");
+ }
+ {
+ slang_operation *rhs = slang_oper_child(assign, 1);
+ slang_operation_literal_bool(rhs, GL_FALSE);
+ }
+ }
+ {
+ slang_operation *brk = slang_oper_child(block, 1);
+ brk->type = SLANG_OPER_BREAK;
+ assert(!brk->children);
+ }
+ }
+ break;
+ case SLANG_OPER_CONTINUE:
+ /* convert continue into a break */
+ oper->type = SLANG_OPER_BREAK;
+ break;
+ case SLANG_OPER_FOR:
+ case SLANG_OPER_DO:
+ case SLANG_OPER_WHILE:
+ /* stop upon finding a nested loop */
+ break;
+ default:
+ /* recurse */
+ {
+ GLuint i;
+ for (i = 0; i < oper->num_children; i++) {
+ replace_break_and_cont(A, slang_oper_child(oper, i));
+ }
+ }
+ }
+}
+
+
+/**
+ * Transform a while-loop so that continue statements are converted to breaks.
+ * Then do normal IR code generation.
+ *
+ * Before:
+ *
+ * while (LOOPCOND) {
+ * A;
+ * if (IFCOND)
+ * continue;
+ * B;
+ * break;
+ * C;
+ * }
+ *
+ * After:
+ *
+ * {
+ * bool _notBreakFlag = 1;
+ * while (_notBreakFlag && LOOPCOND) {
+ * do {
+ * A;
+ * if (IFCOND) {
+ * break; // was continue
+ * }
+ * B;
+ * _notBreakFlag = 0; // was
+ * break; // break
+ * C;
+ * } while (0)
+ * }
+ * }
+ */
static slang_ir_node *
_slang_gen_while_without_continue(slang_assemble_ctx *A, slang_operation *oper)
{
-#if 0
slang_operation *top;
slang_operation *innerBody;
- assert(oper->type == SLANG_OPER_DO);
+ assert(oper->type == SLANG_OPER_WHILE);
top = slang_operation_new(1);
top->type = SLANG_OPER_BLOCK_NEW_SCOPE;
@@ -2440,21 +2528,36 @@ _slang_gen_while_without_continue(slang_assemble_ctx *A, slang_operation *oper)
slang_operation_literal_bool(var->initializer, GL_TRUE);
}
- /* build outer do-loop: do { ... } while (_notBreakFlag && LOOPCOND) */
+ /* build outer while-loop: while (_notBreakFlag && LOOPCOND) { ... } */
{
- slang_operation *outerDo = slang_oper_child(top, 1);
- outerDo->type = SLANG_OPER_DO;
- slang_operation_add_children(outerDo, 2);
+ slang_operation *outerWhile = slang_oper_child(top, 1);
+ outerWhile->type = SLANG_OPER_WHILE;
+ slang_operation_add_children(outerWhile, 2);
- /* inner do-loop */
+ /* _notBreakFlag && LOOPCOND */
{
- slang_operation *innerDo = slang_oper_child(outerDo, 0);
+ slang_operation *cond = slang_oper_child(outerWhile, 0);
+ cond->type = SLANG_OPER_LOGICALAND;
+ slang_operation_add_children(cond, 2);
+ {
+ slang_operation *notBreak = slang_oper_child(cond, 0);
+ slang_operation_identifier(notBreak, A, "_notBreakFlag");
+ }
+ {
+ slang_operation *origCond = slang_oper_child(cond, 1);
+ slang_operation_copy(origCond, slang_oper_child(oper, 0));
+ }
+ }
+
+ /* inner loop */
+ {
+ slang_operation *innerDo = slang_oper_child(outerWhile, 1);
innerDo->type = SLANG_OPER_DO;
slang_operation_add_children(innerDo, 2);
/* copy original do-loop body into inner do-loop's body */
innerBody = slang_oper_child(innerDo, 0);
- slang_operation_copy(innerBody, slang_oper_child(oper, 0));
+ slang_operation_copy(innerBody, slang_oper_child(oper, 1));
innerBody->locals->outer_scope = innerDo->locals;
/* inner do-loop's condition is constant/false */
@@ -2463,21 +2566,6 @@ _slang_gen_while_without_continue(slang_assemble_ctx *A, slang_operation *oper)
slang_operation_literal_bool(constFalse, GL_FALSE);
}
}
-
- /* _notBreakFlag && LOOPCOND */
- {
- slang_operation *cond = slang_oper_child(outerDo, 1);
- cond->type = SLANG_OPER_LOGICALAND;
- slang_operation_add_children(cond, 2);
- {
- slang_operation *notBreak = slang_oper_child(cond, 0);
- slang_operation_identifier(notBreak, A, "_notBreakFlag");
- }
- {
- slang_operation *origCond = slang_oper_child(cond, 1);
- slang_operation_copy(origCond, slang_oper_child(oper, 1));
- }
- }
}
/* Finally, in innerBody,
@@ -2486,10 +2574,10 @@ _slang_gen_while_without_continue(slang_assemble_ctx *A, slang_operation *oper)
*/
replace_break_and_cont(A, innerBody);
- slang_print_tree(top, 0);
+ /*slang_print_tree(top, 0);*/
return _slang_gen_operation(A, top);
-#endif
+
return NULL;
}
@@ -2570,61 +2658,6 @@ _slang_gen_while(slang_assemble_ctx * A, slang_operation *oper)
/**
- * Replace 'break' and 'continue' statements inside a do-while loop.
- * This is a recursive helper function used by _slang_gen_do_without_continue().
- */
-static void
-replace_break_and_cont(slang_assemble_ctx *A, slang_operation *oper)
-{
- switch (oper->type) {
- case SLANG_OPER_BREAK:
- /* replace 'break' with "_notBreakFlag = false; break" */
- {
- slang_operation *block = oper;
- block->type = SLANG_OPER_BLOCK_NEW_SCOPE;
- slang_operation_add_children(block, 2);
- {
- slang_operation *assign = slang_oper_child(block, 0);
- assign->type = SLANG_OPER_ASSIGN;
- slang_operation_add_children(assign, 2);
- {
- slang_operation *lhs = slang_oper_child(assign, 0);
- slang_operation_identifier(lhs, A, "_notBreakFlag");
- }
- {
- slang_operation *rhs = slang_oper_child(assign, 1);
- slang_operation_literal_bool(rhs, GL_FALSE);
- }
- }
- {
- slang_operation *brk = slang_oper_child(block, 1);
- brk->type = SLANG_OPER_BREAK;
- assert(!brk->children);
- }
- }
- break;
- case SLANG_OPER_CONTINUE:
- /* convert continue into a break */
- oper->type = SLANG_OPER_BREAK;
- break;
- case SLANG_OPER_FOR:
- case SLANG_OPER_DO:
- case SLANG_OPER_WHILE:
- /* stop upon finding a nested loop */
- break;
- default:
- /* recurse */
- {
- GLuint i;
- for (i = 0; i < oper->num_children; i++) {
- replace_break_and_cont(A, slang_oper_child(oper, i));
- }
- }
- }
-}
-
-
-/**
* Transform a do-while-loop so that continue statements are converted to breaks.
* Then do normal IR code generation.
*
@@ -2731,7 +2764,7 @@ _slang_gen_do_without_continue(slang_assemble_ctx *A, slang_operation *oper)
*/
replace_break_and_cont(A, innerBody);
- slang_print_tree(top, 0);
+ /*slang_print_tree(top, 0);*/
return _slang_gen_operation(A, top);
}
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