r300/compiler: Handle loops in deadcode analysis.

This also allows us to split the loop emulation into two phases.  A
tranformation phase which either unrolls loops or prepares them to be
emulated, and the emulation phase which unrolls remaining loops until the
instruction limit is reached.  The second phase is completed after the
deadcode analysis in order to get a more accurate count of the number of
instructions in the body of loops.

1 files changed, 16 insertions, 44 deletions

diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_emulate_loops.c b/src/mesa/drivers/dri/r300/compiler/radeon_emulate_loops.c
index 4c5d29f421..1aaaa6cccd 100644
--- a/src/mesa/drivers/dri/r300/compiler/radeon_emulate_loops.c
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_emulate_loops.c
@@ -38,22 +38,6 @@
 
 #define DBG(...) do { if (VERBOSE) fprintf(stderr, __VA_ARGS__); } while(0)
 
-struct emulate_loop_state {
-	struct radeon_compiler * C;
-	struct loop_info * Loops;
-	unsigned int LoopCount;
-	unsigned int LoopReserved;
-};
-
-struct loop_info {
-	struct rc_instruction * BeginLoop;
-	struct rc_instruction * Cond;
-	struct rc_instruction * If;
-	struct rc_instruction * Brk;
-	struct rc_instruction * EndIf;
-	struct rc_instruction * EndLoop;
-};
-
 struct const_value {
 	
 	struct radeon_compiler * C;
@@ -214,8 +198,7 @@ static void get_incr_amount(void * data, struct rc_instruction * inst,
 }
 
 static int transform_const_loop(struct emulate_loop_state * s,
-						struct loop_info * loop,
-						struct rc_instruction * cond)
+						struct loop_info * loop)
 {
 	int end_loops = 1;
 	int iterations;
@@ -228,13 +211,13 @@ static int transform_const_loop(struct emulate_loop_state * s,
 
 	/* Find the counter and the upper limit */
 	
-	if(src_reg_is_immediate(&cond->U.I.SrcReg[0], s->C)){
-		limit = &cond->U.I.SrcReg[0];
-		counter = &cond->U.I.SrcReg[1];
+	if(src_reg_is_immediate(&loop->Cond->U.I.SrcReg[0], s->C)){
+		limit = &loop->Cond->U.I.SrcReg[0];
+		counter = &loop->Cond->U.I.SrcReg[1];
 	}
-	else if(src_reg_is_immediate(&cond->U.I.SrcReg[1], s->C)){
-		limit = &cond->U.I.SrcReg[1];
-		counter = &cond->U.I.SrcReg[0];
+	else if(src_reg_is_immediate(&loop->Cond->U.I.SrcReg[1], s->C)){
+		limit = &loop->Cond->U.I.SrcReg[1];
+		counter = &loop->Cond->U.I.SrcReg[0];
 	}
 	else{
 		DBG("No constant limit.\n");
@@ -414,7 +397,7 @@ static struct rc_instruction * transform_loop(struct emulate_loop_state * s,
 	}
 	
 	/* Check if the number of loops is known at compile time. */
-	if(transform_const_loop(s, loop, ptr)){
+	if(transform_const_loop(s, loop)){
 		return loop->BeginLoop->Next;
 	}
 
@@ -425,9 +408,14 @@ static struct rc_instruction * transform_loop(struct emulate_loop_state * s,
 	return loop->EndLoop;
 }
 
-static void rc_transform_loops(struct emulate_loop_state * s)
+void rc_transform_unroll_loops(struct radeon_compiler *c,
+					struct emulate_loop_state * s)
 {
-	struct rc_instruction * ptr = s->C->Program.Instructions.Next;
+	struct rc_instruction * ptr;
+	
+	memset(s, 0, sizeof(struct emulate_loop_state));
+	s->C = c;
+	ptr = s->C->Program.Instructions.Next;
 	while(ptr != &s->C->Program.Instructions) {
 		if(ptr->Type == RC_INSTRUCTION_NORMAL &&
 					ptr->U.I.Opcode == RC_OPCODE_BGNLOOP){
@@ -440,7 +428,7 @@ static void rc_transform_loops(struct emulate_loop_state * s)
 	}
 }
 
-static void rc_unroll_loops(struct emulate_loop_state *s,
+void rc_emulate_loops(struct emulate_loop_state *s,
 						unsigned int max_instructions)
 {
 	int i;
@@ -456,19 +444,3 @@ static void rc_unroll_loops(struct emulate_loop_state *s,
 		loop_unroll(s, &s->Loops[i], iterations);
 	}
 }
-
-void rc_emulate_loops(struct radeon_compiler *c, unsigned int max_instructions)
-{
-	struct emulate_loop_state s;
-
-	memset(&s, 0, sizeof(struct emulate_loop_state));
-	s.C = c;
-
-	/* We may need to move these two operations to r3xx_(vert|frag)prog.c
-	 * and run the optimization passes between them in order to increase
-	 * the number of unrolls we can do for each loop.
-	 */
-	rc_transform_loops(&s);
-	
-	rc_unroll_loops(&s, max_instructions);
-}