r300/compiler: Implement branch emulation for R300 fragment programs

Signed-off-by: Nicolai Hähnle <nhaehnle@gmail.com>

8 files changed, 512 insertions, 104 deletions

diff --git a/src/mesa/drivers/dri/r300/compiler/Makefile b/src/mesa/drivers/dri/r300/compiler/Makefile
index c8acd3a..e432afc 100644
--- a/src/mesa/drivers/dri/r300/compiler/Makefile
+++ b/src/mesa/drivers/dri/r300/compiler/Makefile
@@ -8,6 +8,7 @@ LIBNAME = r300compiler
 C_SOURCES = \
 		radeon_code.c \
 		radeon_compiler.c \
+		radeon_emulate_branches.c \
 		radeon_program.c \
 		radeon_program_print.c \
 		radeon_opcodes.c \
diff --git a/src/mesa/drivers/dri/r300/compiler/memory_pool.h b/src/mesa/drivers/dri/r300/compiler/memory_pool.h
index ce23c31..42344d0 100644
--- a/src/mesa/drivers/dri/r300/compiler/memory_pool.h
+++ b/src/mesa/drivers/dri/r300/compiler/memory_pool.h
@@ -46,4 +46,35 @@ void memory_pool_init(struct memory_pool * pool);
 void memory_pool_destroy(struct memory_pool * pool);
 void * memory_pool_malloc(struct memory_pool * pool, unsigned int bytes);
 
+
+/**
+ * Generic helper for growing an array that has separate size/count
+ * and reserved counters to accomodate up to num new element.
+ *
+ *  type * Array;
+ *  unsigned int Size;
+ *  unsigned int Reserved;
+ *
+ * memory_pool_array_reserve(pool, type, Array, Size, Reserved, k);
+ * assert(Size + k < Reserved);
+ *
+ * \note Size is not changed by this macro.
+ *
+ * \warning Array, Size, Reserved have to be lvalues and may be evaluated
+ * several times.
+ */
+#define memory_pool_array_reserve(pool, type, array, size, reserved, num) do { \
+	unsigned int _num = (num); \
+	if ((size) + _num > (reserved)) { \
+		unsigned int newreserve = (reserved) * 2; \
+		type * newarray; \
+		if (newreserve < _num) \
+			newreserve = 4 * _num; /* arbitrary heuristic */ \
+		newarray = memory_pool_malloc((pool), newreserve * sizeof(type)); \
+		memcpy(newarray, (array), (size) * sizeof(type)); \
+		(array) = newarray; \
+		(reserved) = newreserve; \
+	} \
+} while(0)
+
 #endif /* MEMORY_POOL_H */
diff --git a/src/mesa/drivers/dri/r300/compiler/r3xx_fragprog.c b/src/mesa/drivers/dri/r300/compiler/r3xx_fragprog.c
index 5fe10db..1e10534 100644
--- a/src/mesa/drivers/dri/r300/compiler/r3xx_fragprog.c
+++ b/src/mesa/drivers/dri/r300/compiler/r3xx_fragprog.c
@@ -25,6 +25,7 @@
 #include <stdio.h>
 
 #include "radeon_dataflow.h"
+#include "radeon_emulate_branches.h"
 #include "radeon_program_alu.h"
 #include "radeon_program_tex.h"
 #include "r300_fragprog.h"
@@ -85,6 +86,14 @@ static void rewrite_depth_out(struct r300_fragment_program_compiler * c)
 	}
 }
 
+static void debug_program_log(struct r300_fragment_program_compiler* c, const char * where)
+{
+	if (c->Base.Debug) {
+		fprintf(stderr, "Fragment Program: %s\n", where);
+		rc_print_program(&c->Base.Program);
+	}
+}
+
 void r3xx_compile_fragment_program(struct r300_fragment_program_compiler* c)
 {
 	rewrite_depth_out(c);
@@ -106,6 +115,10 @@ void r3xx_compile_fragment_program(struct r300_fragment_program_compiler* c)
 		};
 		radeonLocalTransform(&c->Base, 2, transformations);
 
+		debug_program_log(c, "before emulate branches");
+
+		rc_emulate_branches(&c->Base);
+
 		c->Base.SwizzleCaps = &r300_swizzle_caps;
 	}
 
@@ -119,62 +132,41 @@ void r3xx_compile_fragment_program(struct r300_fragment_program_compiler* c)
 	common_transformations[0].function = &radeonTransformALU;
 	radeonLocalTransform(&c->Base, 1, common_transformations);
 
-	if (c->Base.Debug) {
-		fprintf(stderr, "Fragment Program: After native rewrite:\n");
-		rc_print_program(&c->Base.Program);
-		fflush(stderr);
-	}
+	if (c->Base.Error)
+		return;
+
+	debug_program_log(c, "after native rewrite");
 
 	rc_dataflow_deadcode(&c->Base, &dataflow_outputs_mark_use, c);
 	if (c->Base.Error)
 		return;
 
-	if (c->Base.Debug) {
-		fprintf(stderr, "Fragment Program: After deadcode:\n");
-		rc_print_program(&c->Base.Program);
-		fflush(stderr);
-	}
+	debug_program_log(c, "after deadcode");
 
 	rc_dataflow_swizzles(&c->Base);
 	if (c->Base.Error)
 		return;
 
-	if (c->Base.Debug) {
-		fprintf(stderr, "Compiler: after dataflow passes:\n");
-		rc_print_program(&c->Base.Program);
-		fflush(stderr);
-	}
+	debug_program_log(c, "after dataflow passes");
 
 	rc_pair_translate(c);
 	if (c->Base.Error)
 		return;
 
-	if (c->Base.Debug) {
-		fprintf(stderr, "Compiler: after pair translate:\n");
-		rc_print_program(&c->Base.Program);
-		fflush(stderr);
-	}
+	debug_program_log(c, "after pair translate");
 
 	rc_pair_schedule(c);
 	if (c->Base.Error)
 		return;
 
-	if (c->Base.Debug) {
-		fprintf(stderr, "Compiler: after pair scheduling:\n");
-		rc_print_program(&c->Base.Program);
-		fflush(stderr);
-	}
+	debug_program_log(c, "after pair scheduling");
 
 	rc_pair_regalloc(c, c->max_temp_regs);
 
 	if (c->Base.Error)
 		return;
 
-	if (c->Base.Debug) {
-		fprintf(stderr, "Compiler: after pair register allocation:\n");
-		rc_print_program(&c->Base.Program);
-		fflush(stderr);
-	}
+	debug_program_log(c, "after register allocation");
 
 	if (c->is_r500) {
 		r500BuildFragmentProgramHwCode(c);
diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_dataflow.c b/src/mesa/drivers/dri/r300/compiler/radeon_dataflow.c
index cce9166..16e2f3a 100644
--- a/src/mesa/drivers/dri/r300/compiler/radeon_dataflow.c
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_dataflow.c
@@ -160,3 +160,92 @@ void rc_for_all_writes(struct rc_instruction * inst, rc_read_write_fn cb, void *
 		writes_pair(inst, cb, userdata);
 	}
 }
+
+
+static void remap_normal_instruction(struct rc_instruction * fullinst,
+		rc_remap_register_fn cb, void * userdata)
+{
+	struct rc_sub_instruction * inst = &fullinst->U.I;
+	const struct rc_opcode_info * opcode = rc_get_opcode_info(inst->Opcode);
+
+	if (opcode->HasDstReg) {
+		rc_register_file file = inst->DstReg.File;
+		unsigned int index = inst->DstReg.Index;
+
+		cb(userdata, fullinst, &file, &index);
+
+		inst->DstReg.File = file;
+		inst->DstReg.Index = index;
+	}
+
+	for(unsigned int src = 0; src < opcode->NumSrcRegs; ++src) {
+		rc_register_file file = inst->SrcReg[src].File;
+		unsigned int index = inst->SrcReg[src].Index;
+
+		cb(userdata, fullinst, &file, &index);
+
+		inst->SrcReg[src].File = file;
+		inst->SrcReg[src].Index = index;
+	}
+}
+
+static void remap_pair_instruction(struct rc_instruction * fullinst,
+		rc_remap_register_fn cb, void * userdata)
+{
+	struct rc_pair_instruction * inst = &fullinst->U.P;
+
+	if (inst->RGB.WriteMask) {
+		rc_register_file file = RC_FILE_TEMPORARY;
+		unsigned int index = inst->RGB.DestIndex;
+
+		cb(userdata, fullinst, &file, &index);
+
+		inst->RGB.DestIndex = index;
+	}
+
+	if (inst->Alpha.WriteMask) {
+		rc_register_file file = RC_FILE_TEMPORARY;
+		unsigned int index = inst->Alpha.DestIndex;
+
+		cb(userdata, fullinst, &file, &index);
+
+		inst->Alpha.DestIndex = index;
+	}
+
+	for(unsigned int src = 0; src < 3; ++src) {
+		if (inst->RGB.Src[src].Used) {
+			rc_register_file file = inst->RGB.Src[src].File;
+			unsigned int index = inst->RGB.Src[src].Index;
+
+			cb(userdata, fullinst, &file, &index);
+
+			inst->RGB.Src[src].File = file;
+			inst->RGB.Src[src].Index = index;
+		}
+
+		if (inst->Alpha.Src[src].Used) {
+			rc_register_file file = inst->Alpha.Src[src].File;
+			unsigned int index = inst->Alpha.Src[src].Index;
+
+			cb(userdata, fullinst, &file, &index);
+
+			inst->Alpha.Src[src].File = file;
+			inst->Alpha.Src[src].Index = index;
+		}
+	}
+}
+
+
+/**
+ * Remap all register accesses according to the given function.
+ * That is, call the function \p cb for each referenced register (both read and written)
+ * and update the given instruction \p inst accordingly
+ * if it modifies its \ref pfile and \ref pindex contents.
+ */
+void rc_remap_registers(struct rc_instruction * inst, rc_remap_register_fn cb, void * userdata)
+{
+	if (inst->Type == RC_INSTRUCTION_NORMAL)
+		remap_normal_instruction(inst, cb, userdata);
+	else
+		remap_pair_instruction(inst, cb, userdata);
+}
diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_dataflow.h b/src/mesa/drivers/dri/r300/compiler/radeon_dataflow.h
index 5aa4cb6..62cda20 100644
--- a/src/mesa/drivers/dri/r300/compiler/radeon_dataflow.h
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_dataflow.h
@@ -36,13 +36,17 @@ struct rc_swizzle_caps;
 
 
 /**
- * Help analyze the register accesses of instructions.
+ * Help analyze and modify the register accesses of instructions.
  */
 /*@{*/
 typedef void (*rc_read_write_fn)(void * userdata, struct rc_instruction * inst,
 			rc_register_file file, unsigned int index, unsigned int chan);
 void rc_for_all_reads(struct rc_instruction * inst, rc_read_write_fn cb, void * userdata);
 void rc_for_all_writes(struct rc_instruction * inst, rc_read_write_fn cb, void * userdata);
+
+typedef void (*rc_remap_register_fn)(void * userdata, struct rc_instruction * inst,
+			rc_register_file * pfile, unsigned int * pindex);
+void rc_remap_registers(struct rc_instruction * inst, rc_remap_register_fn cb, void * userdata);
 /*@}*/
 
 
diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_emulate_branches.c b/src/mesa/drivers/dri/r300/compiler/radeon_emulate_branches.c
new file mode 100644
index 0000000..d889612
--- /dev/null
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_emulate_branches.c
@@ -0,0 +1,331 @@
+/*
+ * Copyright 2009 Nicolai Hähnle <nhaehnle@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * on the rights to use, copy, modify, merge, publish, distribute, sub
+ * license, and/or sell copies of the Software, and to permit persons to whom
+ * the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE. */
+
+#include "radeon_emulate_branches.h"
+
+#include <stdio.h>
+
+#include "radeon_compiler.h"
+#include "radeon_dataflow.h"
+
+#define VERBOSE 0
+
+#define DBG(...) do { if (VERBOSE) fprintf(stderr, __VA_ARGS__); } while(0)
+
+
+struct proxy_info {
+	unsigned int Proxied:1;
+	unsigned int Index:RC_REGISTER_INDEX_BITS;
+};
+
+struct register_proxies {
+	struct proxy_info Temporary[RC_REGISTER_MAX_INDEX];
+};
+
+struct branch_info {
+	struct rc_instruction * If;
+	struct rc_instruction * Else;
+};
+
+struct emulate_branch_state {
+	struct radeon_compiler * C;
+
+	struct branch_info * Branches;
+	unsigned int BranchCount;
+	unsigned int BranchReserved;
+};
+
+
+static void handle_if(struct emulate_branch_state * s, struct rc_instruction * inst)
+{
+	memory_pool_array_reserve(&s->C->Pool, struct branch_info,
+			s->Branches, s->BranchCount, s->BranchReserved, 1);
+
+	DBG("%s\n", __FUNCTION__);
+
+	struct branch_info * branch = &s->Branches[s->BranchCount++];
+	memset(branch, 0, sizeof(struct branch_info));
+	branch->If = inst;
+
+	/* Make a safety copy of the decision register, because we will need
+	 * it at ENDIF time and it might be overwritten in both branches. */
+	struct rc_instruction * inst_mov = rc_insert_new_instruction(s->C, inst->Prev);
+	inst_mov->U.I.Opcode = RC_OPCODE_MOV;
+	inst_mov->U.I.DstReg.File = RC_FILE_TEMPORARY;
+	inst_mov->U.I.DstReg.Index = rc_find_free_temporary(s->C);
+	inst_mov->U.I.DstReg.WriteMask = RC_MASK_X;
+	inst_mov->U.I.SrcReg[0] = inst->U.I.SrcReg[0];
+
+	inst->U.I.SrcReg[0].File = RC_FILE_TEMPORARY;
+	inst->U.I.SrcReg[0].Index = inst_mov->U.I.DstReg.Index;
+	inst->U.I.SrcReg[0].Swizzle = 0;
+	inst->U.I.SrcReg[0].Abs = 0;
+	inst->U.I.SrcReg[0].Negate = 0;
+}
+
+static void handle_else(struct emulate_branch_state * s, struct rc_instruction * inst)
+{
+	if (!s->BranchCount) {
+		rc_error(s->C, "Encountered ELSE outside of branches");
+		return;
+	}
+
+	DBG("%s\n", __FUNCTION__);
+
+	struct branch_info * branch = &s->Branches[s->BranchCount - 1];
+	branch->Else = inst;
+}
+
+
+struct state_and_proxies {
+	struct emulate_branch_state * S;
+	struct register_proxies * Proxies;
+};
+
+static struct proxy_info * get_proxy_info(struct state_and_proxies * sap,
+			rc_register_file file, unsigned int index)
+{
+	if (file == RC_FILE_TEMPORARY) {
+		return &sap->Proxies->Temporary[index];
+	} else {
+		return 0;
+	}
+}
+
+static void scan_write(void * userdata, struct rc_instruction * inst,
+		rc_register_file file, unsigned int index, unsigned int comp)
+{
+	struct state_and_proxies * sap = userdata;
+	struct proxy_info * proxy = get_proxy_info(sap, file, index);
+
+	if (proxy && !proxy->Proxied) {
+		proxy->Proxied = 1;
+		proxy->Index = rc_find_free_temporary(sap->S->C);
+	}
+}
+
+static void remap_proxy_function(void * userdata, struct rc_instruction * inst,
+		rc_register_file * pfile, unsigned int * pindex)
+{
+	struct state_and_proxies * sap = userdata;
+	struct proxy_info * proxy = get_proxy_info(sap, *pfile, *pindex);
+
+	if (proxy && proxy->Proxied) {
+		*pfile = RC_FILE_TEMPORARY;
+		*pindex = proxy->Index;
+	}
+}
+
+/**
+ * Redirect all writes in the instruction range [begin, end) to proxy
+ * temporary registers.
+ */
+static void allocate_and_insert_proxies(struct emulate_branch_state * s,
+		struct register_proxies * proxies,
+		struct rc_instruction * begin,
+		struct rc_instruction * end)
+{
+	struct state_and_proxies sap;
+
+	sap.S = s;
+	sap.Proxies = proxies;
+
+	for(struct rc_instruction * inst = begin; inst != end; inst = inst->Next) {
+		rc_for_all_writes(inst, scan_write, &sap);
+		rc_remap_registers(inst, remap_proxy_function, &sap);
+	}
+
+	for(unsigned int index = 0; index < RC_REGISTER_MAX_INDEX; ++index) {
+		if (proxies->Temporary[index].Proxied) {
+			struct rc_instruction * inst_mov = rc_insert_new_instruction(s->C, begin->Prev);
+			inst_mov->U.I.Opcode = RC_OPCODE_MOV;
+			inst_mov->U.I.DstReg.File = RC_FILE_TEMPORARY;
+			inst_mov->U.I.DstReg.Index = proxies->Temporary[index].Index;
+			inst_mov->U.I.DstReg.WriteMask = RC_MASK_XYZW;
+			inst_mov->U.I.SrcReg[0].File = RC_FILE_TEMPORARY;
+			inst_mov->U.I.SrcReg[0].Index = index;
+		}
+	}
+}
+
+
+static void inject_cmp(struct emulate_branch_state * s,
+		struct rc_instruction * inst_if,
+		struct rc_instruction * inst_endif,
+		rc_register_file file, unsigned int index,
+		struct proxy_info ifproxy,
+		struct proxy_info elseproxy)
+{
+	struct rc_instruction * inst_cmp = rc_insert_new_instruction(s->C, inst_endif);
+	inst_cmp->U.I.Opcode = RC_OPCODE_CMP;
+	inst_cmp->U.I.DstReg.File = file;
+	inst_cmp->U.I.DstReg.Index = index;
+	inst_cmp->U.I.DstReg.WriteMask = RC_MASK_XYZW;
+	inst_cmp->U.I.SrcReg[0] = inst_if->U.I.SrcReg[0];
+	inst_cmp->U.I.SrcReg[0].Abs = 1;
+	inst_cmp->U.I.SrcReg[0].Negate = RC_MASK_XYZW;
+	inst_cmp->U.I.SrcReg[1].File = RC_FILE_TEMPORARY;
+	inst_cmp->U.I.SrcReg[1].Index = ifproxy.Proxied ? ifproxy.Index : index;
+	inst_cmp->U.I.SrcReg[2].File = RC_FILE_TEMPORARY;
+	inst_cmp->U.I.SrcReg[2].Index = elseproxy.Proxied ? elseproxy.Index : index;
+}
+
+static void handle_endif(struct emulate_branch_state * s, struct rc_instruction * inst)
+{
+	if (!s->BranchCount) {
+		rc_error(s->C, "Encountered ENDIF outside of branches");
+		return;
+	}
+
+	DBG("%s\n", __FUNCTION__);
+
+	struct branch_info * branch = &s->Branches[s->BranchCount - 1];
+	struct register_proxies IfProxies;
+	struct register_proxies ElseProxies;
+
+	memset(&IfProxies, 0, sizeof(IfProxies));
+	memset(&ElseProxies, 0, sizeof(ElseProxies));
+
+	allocate_and_insert_proxies(s, &IfProxies, branch->If->Next, branch->Else ? branch->Else : inst);
+
+	if (branch->Else)
+		allocate_and_insert_proxies(s, &ElseProxies, branch->Else->Next, inst);
+
+	/* Insert the CMP instructions at the end. */
+	for(unsigned int index = 0; index < RC_REGISTER_MAX_INDEX; ++index) {
+		if (IfProxies.Temporary[index].Proxied || ElseProxies.Temporary[index].Proxied) {
+			inject_cmp(s, branch->If, inst, RC_FILE_TEMPORARY, index,
+					IfProxies.Temporary[index], ElseProxies.Temporary[index]);
+		}
+	}
+
+	/* Remove all traces of the branch instructions */
+	rc_remove_instruction(branch->If);
+	if (branch->Else)
+		rc_remove_instruction(branch->Else);
+	rc_remove_instruction(inst);
+
+	s->BranchCount--;
+
+	if (VERBOSE) {
+		DBG("Program after ENDIF handling:\n");
+		rc_print_program(&s->C->Program);
+	}
+}
+
+
+struct remap_output_data {
+	unsigned int Output:RC_REGISTER_INDEX_BITS;
+	unsigned int Temporary:RC_REGISTER_INDEX_BITS;
+};
+
+static void remap_output_function(void * userdata, struct rc_instruction * inst,
+		rc_register_file * pfile, unsigned int * pindex)
+{
+	struct remap_output_data * data = userdata;
+
+	if (*pfile == RC_FILE_OUTPUT && *pindex == data->Output) {
+		*pfile = RC_FILE_TEMPORARY;
+		*pindex = data->Temporary;
+	}
+}
+
+
+/**
+ * Output registers cannot be read from and so cannot be dealt with like
+ * temporary registers.
+ *
+ * We do the simplest thing: If an output registers is written within
+ * a branch, then *all* writes to this register are proxied to a
+ * temporary register, and a final MOV is appended to the end of
+ * the program.
+ */
+static void fix_output_writes(struct emulate_branch_state * s, struct rc_instruction * inst)
+{
+	if (!s->BranchCount)
+		return;
+
+	const struct rc_opcode_info * opcode = rc_get_opcode_info(inst->U.I.Opcode);
+
+	if (!opcode->HasDstReg)
+		return;
+
+	if (inst->U.I.DstReg.File == RC_FILE_OUTPUT) {
+		struct remap_output_data remap;
+
+		remap.Output = inst->U.I.DstReg.Index;
+		remap.Temporary = rc_find_free_temporary(s->C);
+
+		for(struct rc_instruction * inst = s->C->Program.Instructions.Next;
+		    inst != &s->C->Program.Instructions;
+		    inst = inst->Next) {
+			rc_remap_registers(inst, &remap_output_function, &remap);
+		}
+
+		struct rc_instruction * inst_mov = rc_insert_new_instruction(s->C, s->C->Program.Instructions.Prev);
+		inst_mov->U.I.Opcode = RC_OPCODE_MOV;
+		inst_mov->U.I.DstReg.File = RC_FILE_OUTPUT;
+		inst_mov->U.I.DstReg.Index = remap.Output;
+		inst_mov->U.I.DstReg.WriteMask = RC_MASK_XYZW;
+		inst_mov->U.I.SrcReg[0].File = RC_FILE_TEMPORARY;
+		inst_mov->U.I.SrcReg[0].Index = remap.Temporary;
+	}
+}
+
+/**
+ * Remove branch instructions; instead, execute both branches
+ * on different register sets and choose between their results
+ * using CMP instructions in place of the original ENDIF.
+ */
+void rc_emulate_branches(struct radeon_compiler * c)
+{
+	struct emulate_branch_state s;
+
+	memset(&s, 0, sizeof(s));
+	s.C = c;
+
+	/* Untypical loop because we may remove the current instruction */
+	struct rc_instruction * ptr = c->Program.Instructions.Next;
+	while(ptr != &c->Program.Instructions) {
+		struct rc_instruction * inst = ptr;
+		ptr = ptr->Next;
+
+		if (inst->Type == RC_INSTRUCTION_NORMAL) {
+			switch(inst->U.I.Opcode) {
+			case RC_OPCODE_IF:
+				handle_if(&s, inst);
+				break;
+			case RC_OPCODE_ELSE:
+				handle_else(&s, inst);
+				break;
+			case RC_OPCODE_ENDIF:
+				handle_endif(&s, inst);
+				break;
+			default:
+				fix_output_writes(&s, inst);
+				break;
+			}
+		} else {
+			rc_error(c, "%s: unhandled instruction type\n", __FUNCTION__);
+		}
+	}
+}
diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_emulate_branches.h b/src/mesa/drivers/dri/r300/compiler/radeon_emulate_branches.h
new file mode 100644
index 0000000..e07279f
--- /dev/null
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_emulate_branches.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2009 Nicolai Hähnle <nhaehnle@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * on the rights to use, copy, modify, merge, publish, distribute, sub
+ * license, and/or sell copies of the Software, and to permit persons to whom
+ * the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE. */
+
+#ifndef RADEON_EMULATE_BRANCHES_H
+#define RADEON_EMULATE_BRANCHES_H
+
+struct radeon_compiler;
+
+void rc_emulate_branches(struct radeon_compiler * c);
+
+#endif /* RADEON_EMULATE_BRANCHES_H */
diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_pair_regalloc.c b/src/mesa/drivers/dri/r300/compiler/radeon_pair_regalloc.c
index b2fe7f7..fdfee86 100644
--- a/src/mesa/drivers/dri/r300/compiler/radeon_pair_regalloc.c
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_pair_regalloc.c
@@ -196,9 +196,10 @@ static void compute_live_intervals(struct regalloc_state * s)
 	}
 }
 
-static void rewrite_register(struct regalloc_state * s,
+static void remap_register(void * data, struct rc_instruction * inst,
 		rc_register_file * file, unsigned int * index)
 {
+	struct regalloc_state * s = data;
 	const struct register_info * reg;
 
 	if (*file == RC_FILE_TEMPORARY)
@@ -214,74 +215,6 @@ static void rewrite_register(struct regalloc_state * s,
 	}
 }
 
-static void rewrite_normal_instruction(struct regalloc_state * s, struct rc_sub_instruction * inst)
-{
-	const struct rc_opcode_info * opcode = rc_get_opcode_info(inst->Opcode);
-
-	if (opcode->HasDstReg) {
-		rc_register_file file = inst->DstReg.File;
-		unsigned int index = inst->DstReg.Index;
-
-		rewrite_register(s, &file, &index);
-
-		inst->DstReg.File = file;
-		inst->DstReg.Index = index;
-	}
-
-	for(unsigned int src = 0; src < opcode->NumSrcRegs; ++src) {
-		rc_register_file file = inst->SrcReg[src].File;
-		unsigned int index = inst->SrcReg[src].Index;
-
-		rewrite_register(s, &file, &index);
-
-		inst->SrcReg[src].File = file;
-		inst->SrcReg[src].Index = index;
-	}
-}
-
-static void rewrite_pair_instruction(struct regalloc_state * s, struct rc_pair_instruction * inst)
-{
-	if (inst->RGB.WriteMask) {
-		rc_register_file file = RC_FILE_TEMPORARY;
-		unsigned int index = inst->RGB.DestIndex;
-
-		rewrite_register(s, &file, &index);
-
-		inst->RGB.DestIndex = index;
-	}
-
-	if (inst->Alpha.WriteMask) {
-		rc_register_file file = RC_FILE_TEMPORARY;
-		unsigned int index = inst->Alpha.DestIndex;
-
-		rewrite_register(s, &file, &index);
-
-		inst->Alpha.DestIndex = index;
-	}
-
-	for(unsigned int src = 0; src < 3; ++src) {
-		if (inst->RGB.Src[src].Used) {
-			rc_register_file file = inst->RGB.Src[src].File;
-			unsigned int index = inst->RGB.Src[src].Index;
-
-			rewrite_register(s, &file, &index);
-
-			inst->RGB.Src[src].File = file;
-			inst->RGB.Src[src].Index = index;
-		}
-
-		if (inst->Alpha.Src[src].Used) {
-			rc_register_file file = inst->Alpha.Src[src].File;
-			unsigned int index = inst->Alpha.Src[src].Index;
-
-			rewrite_register(s, &file, &index);
-
-			inst->Alpha.Src[src].File = file;
-			inst->Alpha.Src[src].Index = index;
-		}
-	}
-}
-
 static void do_regalloc(struct regalloc_state * s)
 {
 	/* Simple and stupid greedy register allocation */
@@ -310,10 +243,7 @@ static void do_regalloc(struct regalloc_state * s)
 	for(struct rc_instruction * inst = s->C->Program.Instructions.Next;
 	    inst != &s->C->Program.Instructions;
 	    inst = inst->Next) {
-		if (inst->Type == RC_INSTRUCTION_NORMAL)
-			rewrite_normal_instruction(s, &inst->U.I);
-		else
-			rewrite_pair_instruction(s, &inst->U.P);
+		rc_remap_registers(inst, &remap_register, s);
 	}
 }