r300/compiler: Track readers through branches in rc_get_readers()

diff --git a/src/mesa/drivers/dri/r300/compiler/r500_fragprog_emit.c b/src/mesa/drivers/dri/r300/compiler/r500_fragprog_emit.c
index 0311e7c..5da82d9 100644 (file)
--- a/src/mesa/drivers/dri/r300/compiler/r500_fragprog_emit.c
+++ b/src/mesa/drivers/dri/r300/compiler/r500_fragprog_emit.c
@@ -45,9 +45,6 @@
 
 #include "radeon_program_pair.h"
 
-#define MAX_BRANCH_DEPTH_FULL 32
-#define MAX_BRANCH_DEPTH_PARTIAL 4
-
 #define PROG_CODE \
        struct r500_fragment_program_code *code = &c->code->code.r500
 
@@ -509,7 +506,7 @@ static void emit_flowcontrol(struct emit_state * s, struct rc_instruction * inst
                break;
        }
        case RC_OPCODE_IF:
-               if ( s->CurrentBranchDepth >= MAX_BRANCH_DEPTH_FULL) {
+               if ( s->CurrentBranchDepth >= R500_PFS_MAX_BRANCH_DEPTH_FULL) {
                        rc_error(s->C, "Branch depth exceeds hardware limit");
                        return;
                }

diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_code.h b/src/mesa/drivers/dri/r300/compiler/radeon_code.h
index cfb6df2..b69e816 100644 (file)
--- a/src/mesa/drivers/dri/r300/compiler/radeon_code.h
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_code.h
@@ -34,6 +34,8 @@
 #define R500_PFS_MAX_INST         512
 #define R500_PFS_NUM_TEMP_REGS    128
 #define R500_PFS_NUM_CONST_REGS   256
+#define R500_PFS_MAX_BRANCH_DEPTH_FULL 32
+#define R500_PFS_MAX_BRANCH_DEPTH_PARTIAL 4
 
 
 #define STATE_R300_WINDOW_DIMENSION (STATE_INTERNAL_DRIVER+0)

diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_dataflow.c b/src/mesa/drivers/dri/r300/compiler/radeon_dataflow.c
index 2ce0c6e..600be8b 100644 (file)
--- a/src/mesa/drivers/dri/r300/compiler/radeon_dataflow.c
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_dataflow.c
@@ -461,6 +461,12 @@ static rc_opcode get_flow_control_inst(struct rc_instruction * inst)
 
 }
 
+struct branch_write_mask {
+       unsigned int IfWriteMask:4;
+       unsigned int ElseWriteMask:4;
+       unsigned int HasElse:1;
+};
+
 union get_readers_read_cb {
        rc_read_src_fn I;
        rc_pair_read_arg_fn P;
@@ -476,6 +482,8 @@ struct get_readers_callback_data {
        unsigned int DstIndex;
        unsigned int DstMask;
        unsigned int AliveWriteMask;
+       /*  For convenience, this is indexed starting at 1 */
+       struct branch_write_mask BranchMasks[R500_PFS_MAX_BRANCH_DEPTH_FULL + 1];
 };
 
 static void add_reader(
@@ -521,12 +529,12 @@ static unsigned int get_readers_read_callback(
        /* If we make it this far, it means that this source reads from the
         * same register written to by d->ReaderData->Writer. */
 
-       if (cb_data->ReaderData->AbortOnRead) {
+       read_mask = rc_swizzle_to_writemask(swizzle);
+       if (cb_data->ReaderData->AbortOnRead & read_mask) {
                cb_data->ReaderData->Abort = 1;
                return shared_mask;
        }
 
-       read_mask = rc_swizzle_to_writemask(swizzle);
        /* XXX The behavior in this case should be configurable. */
        if ((read_mask & cb_data->AliveWriteMask) != read_mask) {
                cb_data->ReaderData->Abort = 1;
@@ -605,22 +613,8 @@ static void get_readers_write_callback(
 
        if (index == d->DstIndex && file == d->DstFile) {
                unsigned int shared_mask = mask & d->DstMask;
-               if (d->ReaderData->InElse) {
-                       if (shared_mask & d->AliveWriteMask) {
-                               /* We set AbortOnRead here because the
-                                * destination register of d->ReaderData->Writer
-                                * is written to in both the IF and the
-                                * ELSE block of this IF/ELSE statement.
-                                * This means that readers of this
-                                * destination register that follow this IF/ELSE
-                                * statement use the value of different
-                                * instructions depending on the control flow
-                                * decisions made by the program. */
-                               d->ReaderData->AbortOnRead = 1;
-                       }
-               } else {
-                       d->AliveWriteMask &= ~shared_mask;
-               }
+               d->ReaderData->AbortOnRead &= ~shared_mask;
+               d->AliveWriteMask &= ~shared_mask;
        }
 
        if(d->WriteCB)
@@ -645,6 +639,7 @@ static void get_readers_for_single_write(
        d->DstIndex = dst_index;
        d->DstMask = dst_mask;
        d->AliveWriteMask = dst_mask;
+       memset(d->BranchMasks, 0, sizeof(d->BranchMasks));
 
        if (!dst_mask)
                return;
@@ -670,21 +665,53 @@ static void get_readers_for_single_write(
                        d->ReaderData->Abort = 1;
                        return;
                case RC_OPCODE_IF:
-                       /* XXX We can do better here, but this will have to
-                        * do until this dataflow analysis is more mature. */
-                       d->ReaderData->Abort = 1;
                        branch_depth++;
+                       if (branch_depth > R500_PFS_MAX_BRANCH_DEPTH_FULL) {
+                               d->ReaderData->Abort = 1;
+                               return;
+                       }
+                       d->BranchMasks[branch_depth].IfWriteMask =
+                                                       d->AliveWriteMask;
                        break;
                case RC_OPCODE_ELSE:
-                       if (branch_depth == 0)
+                       if (branch_depth == 0) {
                                d->ReaderData->InElse = 1;
+                       } else {
+                               unsigned int temp_mask = d->AliveWriteMask;
+                               d->AliveWriteMask =
+                                       d->BranchMasks[branch_depth].IfWriteMask;
+                               d->BranchMasks[branch_depth].ElseWriteMask =
+                                                               temp_mask;
+                               d->BranchMasks[branch_depth].HasElse = 1;
+                       }
                        break;
                case RC_OPCODE_ENDIF:
                        if (branch_depth == 0) {
-                               d->ReaderData->AbortOnRead = 1;
+                               d->ReaderData->AbortOnRead = d->AliveWriteMask;
                                d->ReaderData->InElse = 0;
                        }
                        else {
+                               struct branch_write_mask * masks =
+                                       &d->BranchMasks[branch_depth];
+
+                               if (masks->HasElse) {
+                                       d->ReaderData->AbortOnRead |=
+                                               masks->IfWriteMask
+                                                       & ~masks->ElseWriteMask;
+                                       d->AliveWriteMask = masks->IfWriteMask
+                                               ^ ((masks->IfWriteMask ^
+                                                       masks->ElseWriteMask)
+                                               & (masks->IfWriteMask
+                                                       ^ d->AliveWriteMask));
+                               } else {
+                                       d->ReaderData->AbortOnRead |=
+                                               masks->IfWriteMask
+                                                       & ~d->AliveWriteMask;
+                                       d->AliveWriteMask = masks->IfWriteMask;
+
+                               }
+                               memset(masks, 0,
+                                       sizeof(struct branch_write_mask));
                                branch_depth--;
                        }
                        break;
@@ -692,21 +719,22 @@ static void get_readers_for_single_write(
                        break;
                }
 
-               if (!d->ReaderData->InElse) {
-                       if (tmp->Type == RC_INSTRUCTION_NORMAL) {
-                               rc_for_all_reads_src(tmp,
-                                       get_readers_normal_read_callback, d);
-                       } else {
-                               rc_pair_for_all_reads_arg(tmp,
-                                       get_readers_pair_read_callback, d);
-                       }
+               if (d->ReaderData->InElse)
+                       continue;
+
+               if (tmp->Type == RC_INSTRUCTION_NORMAL) {
+                       rc_for_all_reads_src(tmp,
+                               get_readers_normal_read_callback, d);
+               } else {
+                       rc_pair_for_all_reads_arg(tmp,
+                               get_readers_pair_read_callback, d);
                }
                rc_for_all_writes_mask(tmp, get_readers_write_callback, d);
 
                if (d->ReaderData->Abort)
                        return;
 
-               if (!d->AliveWriteMask)
+               if (branch_depth == 0 && !d->AliveWriteMask)
                        return;
        }
 }

diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_optimize.c b/src/mesa/drivers/dri/r300/compiler/radeon_optimize.c
index 0f707d8..2eb5484 100644 (file)
--- a/src/mesa/drivers/dri/r300/compiler/radeon_optimize.c
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_optimize.c
@@ -112,11 +112,11 @@ static void src_clobbered_reads_cb(
            && src->Index == sc_data->Index
            && (rc_swizzle_to_writemask(src->Swizzle) & sc_data->Mask)) {
 
-               sc_data->ReaderData->AbortOnRead = 1;
+               sc_data->ReaderData->AbortOnRead = RC_MASK_XYZW;
        }
 
        if (src->RelAddr && sc_data->File == RC_FILE_ADDRESS) {
-               sc_data->ReaderData->AbortOnRead = 1;
+               sc_data->ReaderData->AbortOnRead = RC_MASK_XYZW;
        }
 }