nv50: don't overwrite sources before they're used

This would have happened in p.e. ADD TEMP[0], TEMP[0].xyxy, TEMP[1]
or RCP/RSQ TEMP[i], TEMP[i].

diff --git a/src/gallium/drivers/nv50/nv50_program.c b/src/gallium/drivers/nv50/nv50_program.c
index 80b763011338040daa6b00cc228a12d46947850e..fa131339228a7412a021bee13debd4f7a0e5d24b 100644 (file)
--- a/src/gallium/drivers/nv50/nv50_program.c
+++ b/src/gallium/drivers/nv50/nv50_program.c
@@ -196,6 +196,22 @@ alloc_temp(struct nv50_pc *pc, struct nv50_reg *dst)
        return NULL;
 }
 
+/* Assign the hw of the discarded temporary register src
+ * to the tgsi register dst and free src.
+ */
+static void
+assimilate_temp(struct nv50_pc *pc, struct nv50_reg *dst, struct nv50_reg *src)
+{
+       assert(src->index == -1 && src->hw != -1);
+
+       if (dst->hw != -1)
+               pc->r_temp[dst->hw] = NULL;
+       pc->r_temp[src->hw] = dst;
+       dst->hw = src->hw;
+
+       FREE(src);
+}
+
 static void
 free_temp(struct nv50_pc *pc, struct nv50_reg *r)
 {
@@ -852,17 +868,8 @@ emit_lit(struct nv50_pc *pc, struct nv50_reg **dst, unsigned mask,
        struct nv50_reg *pos128 = alloc_immd(pc,  127.999999);
        struct nv50_reg *tmp[4];
 
-       if (mask & (1 << 0))
-               emit_mov(pc, dst[0], one);
-
-       if (mask & (1 << 3))
-               emit_mov(pc, dst[3], one);
-
        if (mask & (3 << 1)) {
-               if (mask & (1 << 1))
-                       tmp[0] = dst[1];
-               else
-                       tmp[0] = temp_temp(pc);
+               tmp[0] = alloc_temp(pc, NULL);
                emit_minmax(pc, 4, tmp[0], src[0], zero);
        }
 
@@ -881,6 +888,19 @@ emit_lit(struct nv50_pc *pc, struct nv50_reg **dst, unsigned mask,
                set_pred(pc, 3, 0, pc->p->exec_tail);
        }
 
+       if (mask & (1 << 1))
+               assimilate_temp(pc, dst[1], tmp[0]);
+       else
+       if (mask & (1 << 2))
+               free_temp(pc, tmp[0]);
+
+       /* do this last, in case src[i,j] == dst[0,3] */
+       if (mask & (1 << 0))
+               emit_mov(pc, dst[0], one);
+
+       if (mask & (1 << 3))
+               emit_mov(pc, dst[3], one);
+
        FREE(pos128);
        FREE(neg128);
        FREE(zero);
@@ -1016,12 +1036,40 @@ tgsi_src(struct nv50_pc *pc, int chan, const struct tgsi_full_src_register *src)
        return r;
 }
 
+/* returns TRUE if instruction can overwrite sources before they're read */
+static boolean
+direct2dest_op(const struct tgsi_full_instruction *insn)
+{
+       if (insn->Instruction.Saturate)
+               return FALSE;
+
+       switch (insn->Instruction.Opcode) {
+       case TGSI_OPCODE_COS:
+       case TGSI_OPCODE_DP3:
+       case TGSI_OPCODE_DP4:
+       case TGSI_OPCODE_DPH:
+       case TGSI_OPCODE_KIL:
+       case TGSI_OPCODE_LIT:
+       case TGSI_OPCODE_POW:
+       case TGSI_OPCODE_RCP:
+       case TGSI_OPCODE_RSQ:
+       case TGSI_OPCODE_SCS:
+       case TGSI_OPCODE_SIN:
+       case TGSI_OPCODE_TEX:
+       case TGSI_OPCODE_TXP:
+               return FALSE;
+       default:
+               return TRUE;
+       }
+}
+
 static boolean
 nv50_program_tx_insn(struct nv50_pc *pc, const union tgsi_full_token *tok)
 {
        const struct tgsi_full_instruction *inst = &tok->FullInstruction;
        struct nv50_reg *rdst[4], *dst[4], *src[3][4], *temp;
        unsigned mask, sat, unit;
+       boolean assimilate = FALSE;
        int i, c;
 
        mask = inst->FullDstRegisters[0].DstRegister.WriteMask;
@@ -1053,6 +1101,25 @@ nv50_program_tx_insn(struct nv50_pc *pc, const union tgsi_full_token *tok)
                        rdst[c] = dst[c];
                        dst[c] = temp_temp(pc);
                }
+       } else
+       if (direct2dest_op(inst)) {
+               for (c = 0; c < 4; c++) {
+                       if (!dst[c] || dst[c]->type != P_TEMP)
+                               continue;
+
+                       for (i = c + 1; i < 4; i++) {
+                               if (dst[c] == src[0][i] ||
+                                   dst[c] == src[1][i] ||
+                                   dst[c] == src[2][i])
+                                       break;
+                       }
+                       if (i == 4)
+                               continue;
+
+                       assimilate = TRUE;
+                       rdst[c] = dst[c];
+                       dst[c] = alloc_temp(pc, NULL);
+               }
        }
 
        switch (inst->Instruction.Opcode) {
@@ -1227,14 +1294,14 @@ nv50_program_tx_insn(struct nv50_pc *pc, const union tgsi_full_token *tok)
                }
                break;
        case TGSI_OPCODE_RCP:
-               for (c = 0; c < 4; c++) {
+               for (c = 3; c >= 0; c--) {
                        if (!(mask & (1 << c)))
                                continue;
                        emit_flop(pc, 0, dst[c], src[0][0]);
                }
                break;
        case TGSI_OPCODE_RSQ:
-               for (c = 0; c < 4; c++) {
+               for (c = 3; c >= 0; c--) {
                        if (!(mask & (1 << c)))
                                continue;
                        emit_flop(pc, 2, dst[c], src[0][0]);
@@ -1351,6 +1418,10 @@ nv50_program_tx_insn(struct nv50_pc *pc, const union tgsi_full_token *tok)
                        set_src_0(pc, dst[c], e);
                        emit(pc, e);
                }
+       } else if (assimilate) {
+               for (c = 0; c < 4; c++)
+                       if (rdst[c])
+                               assimilate_temp(pc, rdst[c], dst[c]);
        }
 
        for (i = 0; i < inst->Instruction.NumSrcRegs; i++) {