r300/compiler: improve register allocation with indexable temporaries for VS

Register allocation can now reallocate temporaries right after the last indexed
source operand, instead of being disabled for the whole shader.

diff --git a/src/mesa/drivers/dri/r300/compiler/r3xx_vertprog.c b/src/mesa/drivers/dri/r300/compiler/r3xx_vertprog.c
index 3e8a8236c05facd0d79452a3a347c076684a8c78..1628078a3279224c24433ff2b728dff939a76d63 100644 (file)
--- a/src/mesa/drivers/dri/r300/compiler/r3xx_vertprog.c
+++ b/src/mesa/drivers/dri/r300/compiler/r3xx_vertprog.c
@@ -665,12 +665,15 @@ static void allocate_temporary_registers(struct radeon_compiler *c, void *user)
        struct rc_instruction *inst;
        struct rc_instruction *end_loop = NULL;
        unsigned int num_orig_temps = 0;
-       char hwtemps[R300_VS_MAX_TEMPS];
+       char hwtemps[RC_REGISTER_MAX_INDEX];
        struct temporary_allocation * ta;
        unsigned int i, j;
+       struct rc_instruction *last_inst_src_reladdr = NULL;
 
        memset(hwtemps, 0, sizeof(hwtemps));
 
+       rc_recompute_ips(c);
+
        /* Pass 1: Count original temporaries. */
        for(inst = compiler->Base.Program.Instructions.Next; inst != &compiler->Base.Program.Instructions; inst = inst->Next) {
                const struct rc_opcode_info * opcode = rc_get_opcode_info(inst->U.I.Opcode);
@@ -690,7 +693,8 @@ static void allocate_temporary_registers(struct radeon_compiler *c, void *user)
                }
        }
 
-       /* Pass 2: If there is relative addressing of temporaries, we cannot change register indices. Give up. */
+       /* Pass 2: If there is relative addressing of dst temporaries, we cannot change register indices. Give up.
+        * For src temporaries, save the last instruction which uses relative addressing. */
        for (inst = compiler->Base.Program.Instructions.Next; inst != &compiler->Base.Program.Instructions; inst = inst->Next) {
                const struct rc_opcode_info *opcode = rc_get_opcode_info(inst->U.I.Opcode);
 
@@ -701,7 +705,7 @@ static void allocate_temporary_registers(struct radeon_compiler *c, void *user)
                for (i = 0; i < opcode->NumSrcRegs; ++i) {
                        if (inst->U.I.SrcReg[i].File == RC_FILE_TEMPORARY &&
                            inst->U.I.SrcReg[i].RelAddr) {
-                               return;
+                               last_inst_src_reladdr = inst;
                        }
                }
        }
@@ -739,9 +743,26 @@ static void allocate_temporary_registers(struct radeon_compiler *c, void *user)
                }
 
                for (i = 0; i < opcode->NumSrcRegs; ++i) {
-                       if (inst->U.I.SrcReg[i].File == RC_FILE_TEMPORARY)
-                               ta[inst->U.I.SrcReg[i].Index].LastRead =
-                                               end_loop ? end_loop : inst;
+                       if (inst->U.I.SrcReg[i].File == RC_FILE_TEMPORARY) {
+                               struct rc_instruction *last_read;
+
+                               /* From "last_inst_src_reladdr", "end_loop", and "inst",
+                                * select the instruction with the highest instruction index (IP).
+                                * Note that "end_loop", if available, has always a higher index than "inst". */
+                               if (last_inst_src_reladdr) {
+                                       if (end_loop) {
+                                               last_read = last_inst_src_reladdr->IP > end_loop->IP ?
+                                                           last_inst_src_reladdr : end_loop;
+                                       } else {
+                                               last_read = last_inst_src_reladdr->IP > inst->IP ?
+                                                           last_inst_src_reladdr : inst;
+                                       }
+                               } else {
+                                       last_read = end_loop ? end_loop : inst;
+                               }
+
+                               ta[inst->U.I.SrcReg[i].Index].LastRead = last_read;
+                       }
                }
        }
 
@@ -749,13 +770,15 @@ static void allocate_temporary_registers(struct radeon_compiler *c, void *user)
        for(inst = compiler->Base.Program.Instructions.Next; inst != &compiler->Base.Program.Instructions; inst = inst->Next) {
                const struct rc_opcode_info * opcode = rc_get_opcode_info(inst->U.I.Opcode);
 
-               for (i = 0; i < opcode->NumSrcRegs; ++i) {
-                       if (inst->U.I.SrcReg[i].File == RC_FILE_TEMPORARY) {
-                               unsigned int orig = inst->U.I.SrcReg[i].Index;
-                               inst->U.I.SrcReg[i].Index = ta[orig].HwTemp;
+               if (!last_inst_src_reladdr || last_inst_src_reladdr->IP < inst->IP) {
+                       for (i = 0; i < opcode->NumSrcRegs; ++i) {
+                               if (inst->U.I.SrcReg[i].File == RC_FILE_TEMPORARY) {
+                                       unsigned int orig = inst->U.I.SrcReg[i].Index;
+                                       inst->U.I.SrcReg[i].Index = ta[orig].HwTemp;
 
-                               if (ta[orig].Allocated && inst == ta[orig].LastRead)
-                                       hwtemps[ta[orig].HwTemp] = 0;
+                                       if (ta[orig].Allocated && inst == ta[orig].LastRead)
+                                               hwtemps[ta[orig].HwTemp] = 0;
+                               }
                        }
                }
 
@@ -764,16 +787,22 @@ static void allocate_temporary_registers(struct radeon_compiler *c, void *user)
                                unsigned int orig = inst->U.I.DstReg.Index;
 
                                if (!ta[orig].Allocated) {
-                                       for(j = 0; j < R300_VS_MAX_TEMPS; ++j) {
+                                       for(j = 0; j < c->max_temp_regs; ++j) {
                                                if (!hwtemps[j])
                                                        break;
                                        }
-                                       if (j >= R300_VS_MAX_TEMPS) {
-                                               fprintf(stderr, "Out of hw temporaries\n");
+                                       if (j >= c->max_temp_regs) {
+                                               rc_error(c, "Too many temporaries\n");
+                                               return;
                                        } else {
                                                ta[orig].Allocated = 1;
-                                               ta[orig].HwTemp = j;
-                                               hwtemps[j] = 1;
+                                               if (last_inst_src_reladdr &&
+                                                   last_inst_src_reladdr->IP > inst->IP) {
+                                                       ta[orig].HwTemp = orig;
+                                               } else {
+                                                       ta[orig].HwTemp = j;
+                                               }
+                                               hwtemps[ta[orig].HwTemp] = 1;
                                        }
                                }