freedreno/ir3: add SSBO get_buffer_size() support
[mesa.git] / src / gallium / drivers / freedreno / ir3 / ir3_cp.c
index f4c825b2ab602b6a3fe93ac4e5da5fea200c6bf7..8c907eb5a534d9be15b7d6849d6793b1c78d1741 100644 (file)
 #include "freedreno_util.h"
 
 #include "ir3.h"
+#include "ir3_shader.h"
 
 /*
  * Copy Propagate:
  */
 
+struct ir3_cp_ctx {
+       struct ir3 *shader;
+       struct ir3_shader_variant *so;
+       unsigned immediate_idx;
+};
+
 /* is it a type preserving mov, with ok flags? */
 static bool is_eligible_mov(struct ir3_instruction *instr, bool allow_flags)
 {
@@ -41,25 +48,31 @@ static bool is_eligible_mov(struct ir3_instruction *instr, bool allow_flags)
                struct ir3_register *dst = instr->regs[0];
                struct ir3_register *src = instr->regs[1];
                struct ir3_instruction *src_instr = ssa(src);
+
+               /* only if mov src is SSA (not const/immed): */
+               if (!src_instr)
+                       return false;
+
+               /* no indirect: */
                if (dst->flags & IR3_REG_RELATIV)
                        return false;
                if (src->flags & IR3_REG_RELATIV)
                        return false;
+
                if (!allow_flags)
                        if (src->flags & (IR3_REG_FABS | IR3_REG_FNEG |
                                        IR3_REG_SABS | IR3_REG_SNEG | IR3_REG_BNOT))
                                return false;
-               if (!src_instr)
-                       return false;
+
                /* TODO: remove this hack: */
-               if (is_meta(src_instr) && (src_instr->opc == OPC_META_FO))
+               if (src_instr->opc == OPC_META_FO)
                        return false;
                /* TODO: we currently don't handle left/right neighbors
                 * very well when inserting parallel-copies into phi..
                 * to avoid problems don't eliminate a mov coming out
                 * of phi..
                 */
-               if (is_meta(src_instr) && (src_instr->opc == OPC_META_PHI))
+               if (src_instr->opc == OPC_META_PHI)
                        return false;
                return true;
        }
@@ -82,20 +95,25 @@ static bool valid_flags(struct ir3_instruction *instr, unsigned n,
        unsigned valid_flags;
        flags = cp_flags(flags);
 
-       /* clear flags that are 'ok' */
-       switch (instr->category) {
+       /* If destination is indirect, then source cannot be.. at least
+        * I don't think so..
+        */
+       if ((instr->regs[0]->flags & IR3_REG_RELATIV) &&
+                       (flags & IR3_REG_RELATIV))
+               return false;
+
+       /* TODO it seems to *mostly* work to cp RELATIV, except we get some
+        * intermittent piglit variable-indexing fails.  Newer blob driver
+        * doesn't seem to cp these.  Possibly this is hw workaround?  Not
+        * sure, but until that is understood better, lets just switch off
+        * cp for indirect src's:
+        */
+       if (flags & IR3_REG_RELATIV)
+               return false;
+
+       switch (opc_cat(instr->opc)) {
        case 1:
-               valid_flags = IR3_REG_IMMED | IR3_REG_RELATIV;
-               if (flags & ~valid_flags)
-                       return false;
-               break;
-       case 5:
-               /* no flags allowed */
-               if (flags)
-                       return false;
-               break;
-       case 6:
-               valid_flags = IR3_REG_IMMED;
+               valid_flags = IR3_REG_IMMED | IR3_REG_CONST | IR3_REG_RELATIV;
                if (flags & ~valid_flags)
                        return false;
                break;
@@ -150,11 +168,40 @@ static bool valid_flags(struct ir3_instruction *instr, unsigned n,
        case 4:
                /* seems like blob compiler avoids const as src.. */
                /* TODO double check if this is still the case on a4xx */
-               if (flags & IR3_REG_CONST)
+               if (flags & (IR3_REG_CONST | IR3_REG_IMMED))
                        return false;
                if (flags & (IR3_REG_SABS | IR3_REG_SNEG))
                        return false;
                break;
+       case 5:
+               /* no flags allowed */
+               if (flags)
+                       return false;
+               break;
+       case 6:
+               valid_flags = IR3_REG_IMMED;
+               if (flags & ~valid_flags)
+                       return false;
+
+               if (flags & IR3_REG_IMMED) {
+                       /* doesn't seem like we can have immediate src for store
+                        * instructions:
+                        *
+                        * TODO this restriction could also apply to load instructions,
+                        * but for load instructions this arg is the address (and not
+                        * really sure any good way to test a hard-coded immed addr src)
+                        */
+                       if (is_store(instr) && (n == 1))
+                               return false;
+
+                       /* disallow CP into anything but the SSBO slot argument for
+                        * atomics:
+                        */
+                       if (is_atomic(instr->opc) && (n != 0))
+                               return false;
+               }
+
+               break;
        }
 
        return true;
@@ -163,8 +210,10 @@ static bool valid_flags(struct ir3_instruction *instr, unsigned n,
 /* propagate register flags from src to dst.. negates need special
  * handling to cancel each other out.
  */
-static void combine_flags(unsigned *dstflags, unsigned srcflags)
+static void combine_flags(unsigned *dstflags, struct ir3_instruction *src)
 {
+       unsigned srcflags = src->regs[1]->flags;
+
        /* if what we are combining into already has (abs) flags,
         * we can drop (neg) from src:
         */
@@ -183,17 +232,78 @@ static void combine_flags(unsigned *dstflags, unsigned srcflags)
                *dstflags ^= IR3_REG_SNEG;
        if (srcflags & IR3_REG_BNOT)
                *dstflags ^= IR3_REG_BNOT;
-}
 
-static struct ir3_instruction * instr_cp(struct ir3_instruction *instr, unsigned *flags);
+       *dstflags &= ~IR3_REG_SSA;
+       *dstflags |= srcflags & IR3_REG_SSA;
+       *dstflags |= srcflags & IR3_REG_CONST;
+       *dstflags |= srcflags & IR3_REG_IMMED;
+       *dstflags |= srcflags & IR3_REG_RELATIV;
+       *dstflags |= srcflags & IR3_REG_ARRAY;
+
+       /* if src of the src is boolean we can drop the (abs) since we know
+        * the source value is already a postitive integer.  This cleans
+        * up the absnegs that get inserted when converting between nir and
+        * native boolean (see ir3_b2n/n2b)
+        */
+       struct ir3_instruction *srcsrc = ssa(src->regs[1]);
+       if (srcsrc && is_bool(srcsrc))
+               *dstflags &= ~IR3_REG_SABS;
+}
 
-/* the "plain" MAD's (ie. the ones that don't shift first src prior to
- * multiply) can swap their first two srcs if src[0] is !CONST and
- * src[1] is CONST:
- */
-static bool is_valid_mad(struct ir3_instruction *instr)
+static struct ir3_register *
+lower_immed(struct ir3_cp_ctx *ctx, struct ir3_register *reg, unsigned new_flags)
 {
-       return (instr->category == 3) && is_mad(instr->opc);
+       unsigned swiz, idx, i;
+
+       reg = ir3_reg_clone(ctx->shader, reg);
+
+       /* in some cases, there are restrictions on (abs)/(neg) plus const..
+        * so just evaluate those and clear the flags:
+        */
+       if (new_flags & IR3_REG_SABS) {
+               reg->iim_val = abs(reg->iim_val);
+               new_flags &= ~IR3_REG_SABS;
+       }
+
+       if (new_flags & IR3_REG_FABS) {
+               reg->fim_val = fabs(reg->fim_val);
+               new_flags &= ~IR3_REG_FABS;
+       }
+
+       if (new_flags & IR3_REG_SNEG) {
+               reg->iim_val = -reg->iim_val;
+               new_flags &= ~IR3_REG_SNEG;
+       }
+
+       if (new_flags & IR3_REG_FNEG) {
+               reg->fim_val = -reg->fim_val;
+               new_flags &= ~IR3_REG_FNEG;
+       }
+
+       for (i = 0; i < ctx->immediate_idx; i++) {
+               swiz = i % 4;
+               idx  = i / 4;
+
+               if (ctx->so->immediates[idx].val[swiz] == reg->uim_val) {
+                       break;
+               }
+       }
+
+       if (i == ctx->immediate_idx) {
+               /* need to generate a new immediate: */
+               swiz = i % 4;
+               idx  = i / 4;
+               ctx->so->immediates[idx].val[swiz] = reg->uim_val;
+               ctx->so->immediates_count = idx + 1;
+               ctx->immediate_idx++;
+       }
+
+       new_flags &= ~IR3_REG_IMMED;
+       new_flags |= IR3_REG_CONST;
+       reg->flags = new_flags;
+       reg->num = i + (4 * ctx->so->constbase.immediate);
+
+       return reg;
 }
 
 /**
@@ -204,60 +314,61 @@ static bool is_valid_mad(struct ir3_instruction *instr)
  * instruction).
  */
 static void
-reg_cp(struct ir3_instruction *instr, struct ir3_register *reg, unsigned n)
+reg_cp(struct ir3_cp_ctx *ctx, struct ir3_instruction *instr,
+               struct ir3_register *reg, unsigned n)
 {
-       unsigned src_flags = 0, new_flags;
-       struct ir3_instruction *src_instr;
+       struct ir3_instruction *src = ssa(reg);
 
-       if (is_meta(instr)) {
-               /* meta instructions cannot fold up register
-                * flags.. they are usually src for texture
-                * fetch, etc, where we cannot specify abs/neg
-                */
-               reg->instr = instr_cp(reg->instr, NULL);
+       /* don't propagate copies into a PHI, since we don't know if the
+        * src block executed:
+        */
+       if (instr->opc == OPC_META_PHI)
                return;
-       }
 
-       src_instr = instr_cp(reg->instr, &src_flags);
+       if (is_eligible_mov(src, true)) {
+               /* simple case, no immed/const/relativ, only mov's w/ ssa src: */
+               struct ir3_register *src_reg = src->regs[1];
+               unsigned new_flags = reg->flags;
 
-       new_flags = reg->flags;
-       combine_flags(&new_flags, src_flags);
+               combine_flags(&new_flags, src);
 
-       reg->flags = new_flags;
-       reg->instr = src_instr;
-
-       if (!valid_flags(instr, n, reg->flags)) {
-               /* insert an absneg.f */
-               if (reg->flags & (IR3_REG_SNEG | IR3_REG_SABS | IR3_REG_BNOT)) {
-                       debug_assert(!(reg->flags & (IR3_REG_FNEG | IR3_REG_FABS)));
-                       reg->instr = ir3_ABSNEG_S(instr->block,
-                                       reg->instr, cp_flags(src_flags));
-               } else {
-                       debug_assert(!(reg->flags & (IR3_REG_SNEG | IR3_REG_SABS | IR3_REG_BNOT)));
-                       reg->instr = ir3_ABSNEG_F(instr->block,
-                                       reg->instr, cp_flags(src_flags));
+               if (valid_flags(instr, n, new_flags)) {
+                       if (new_flags & IR3_REG_ARRAY) {
+                               debug_assert(!(reg->flags & IR3_REG_ARRAY));
+                               reg->array = src_reg->array;
+                       }
+                       reg->flags = new_flags;
+                       reg->instr = ssa(src_reg);
                }
-               reg->flags &= ~cp_flags(src_flags);
-               debug_assert(valid_flags(instr, n, reg->flags));
-               /* send it through instr_cp() again since
-                * the absneg src might be a mov from const
-                * that could be cleaned up:
-                */
-               reg->instr = instr_cp(reg->instr, NULL);
-               return;
-       }
 
-       if (is_same_type_mov(reg->instr)) {
-               struct ir3_register *src_reg = reg->instr->regs[1];
-               unsigned new_flags = src_reg->flags;
+               src = ssa(reg);      /* could be null for IR3_REG_ARRAY case */
+               if (!src)
+                       return;
+       } else if (is_same_type_mov(src) &&
+                       /* cannot collapse const/immed/etc into meta instrs: */
+                       !is_meta(instr)) {
+               /* immed/const/etc cases, which require some special handling: */
+               struct ir3_register *src_reg = src->regs[1];
+               unsigned new_flags = reg->flags;
 
-               combine_flags(&new_flags, reg->flags);
+               combine_flags(&new_flags, src);
 
                if (!valid_flags(instr, n, new_flags)) {
+                       /* See if lowering an immediate to const would help. */
+                       if (valid_flags(instr, n, (new_flags & ~IR3_REG_IMMED) | IR3_REG_CONST)) {
+                               debug_assert(new_flags & IR3_REG_IMMED);
+                               instr->regs[n + 1] = lower_immed(ctx, src_reg, new_flags);
+                               return;
+                       }
+
                        /* special case for "normal" mad instructions, we can
                         * try swapping the first two args if that fits better.
+                        *
+                        * the "plain" MAD's (ie. the ones that don't shift first
+                        * src prior to multiply) can swap their first two srcs if
+                        * src[0] is !CONST and src[1] is CONST:
                         */
-                       if ((n == 1) && is_valid_mad(instr) &&
+                       if ((n == 1) && is_mad(instr->opc) &&
                                        !(instr->regs[0 + 1]->flags & (IR3_REG_CONST | IR3_REG_RELATIV)) &&
                                        valid_flags(instr, 0, new_flags)) {
                                /* swap src[0] and src[1]: */
@@ -287,6 +398,16 @@ reg_cp(struct ir3_instruction *instr, struct ir3_register *reg, unsigned n)
                                        conflicts(instr->address, reg->instr->address))
                                return;
 
+                       /* This seems to be a hw bug, or something where the timings
+                        * just somehow don't work out.  This restriction may only
+                        * apply if the first src is also CONST.
+                        */
+                       if ((opc_cat(instr->opc) == 3) && (n == 2) &&
+                                       (src_reg->flags & IR3_REG_RELATIV) &&
+                                       (src_reg->array.offset == 0))
+                               return;
+
+                       src_reg = ir3_reg_clone(instr->block->shader, src_reg);
                        src_reg->flags = new_flags;
                        instr->regs[n+1] = src_reg;
 
@@ -298,6 +419,7 @@ reg_cp(struct ir3_instruction *instr, struct ir3_register *reg, unsigned n)
 
                if ((src_reg->flags & IR3_REG_RELATIV) &&
                                !conflicts(instr->address, reg->instr->address)) {
+                       src_reg = ir3_reg_clone(instr->block->shader, src_reg);
                        src_reg->flags = new_flags;
                        instr->regs[n+1] = src_reg;
                        ir3_instr_set_address(instr, reg->instr->address);
@@ -316,10 +438,9 @@ reg_cp(struct ir3_instruction *instr, struct ir3_register *reg, unsigned n)
                if (src_reg->flags & IR3_REG_IMMED) {
                        int32_t iim_val = src_reg->iim_val;
 
-                       debug_assert((instr->category == 1) ||
-                                       (instr->category == 6) ||
-                                       ((instr->category == 2) &&
-                                               ir3_cat2_int(instr->opc)));
+                       debug_assert((opc_cat(instr->opc) == 1) ||
+                                       (opc_cat(instr->opc) == 6) ||
+                                       ir3_cat2_int(instr->opc));
 
                        if (new_flags & IR3_REG_SABS)
                                iim_val = abs(iim_val);
@@ -330,11 +451,17 @@ reg_cp(struct ir3_instruction *instr, struct ir3_register *reg, unsigned n)
                        if (new_flags & IR3_REG_BNOT)
                                iim_val = ~iim_val;
 
-                       if (!(iim_val & ~0x3ff)) {
+                       /* other than category 1 (mov) we can only encode up to 10 bits: */
+                       if ((instr->opc == OPC_MOV) ||
+                                       !((iim_val & ~0x3ff) && (-iim_val & ~0x3ff))) {
                                new_flags &= ~(IR3_REG_SABS | IR3_REG_SNEG | IR3_REG_BNOT);
+                               src_reg = ir3_reg_clone(instr->block->shader, src_reg);
                                src_reg->flags = new_flags;
                                src_reg->iim_val = iim_val;
                                instr->regs[n+1] = src_reg;
+                       } else if (valid_flags(instr, n, (new_flags & ~IR3_REG_IMMED) | IR3_REG_CONST)) {
+                               /* See if lowering an immediate to const would help. */
+                               instr->regs[n+1] = lower_immed(ctx, src_reg, new_flags);
                        }
 
                        return;
@@ -342,74 +469,127 @@ reg_cp(struct ir3_instruction *instr, struct ir3_register *reg, unsigned n)
        }
 }
 
-/**
- * Given an SSA src (instruction), return the one with extraneous
- * mov's removed, ie, for (to copy NIR syntax):
- *
- *   vec1 ssa1 = fadd <something>, <somethingelse>
- *   vec1 ssa2 = fabs ssa1
- *   vec1 ssa3 = fneg ssa1
- *
- * then calling instr_cp(ssa3, &flags) would return ssa1 with
- * (IR3_REG_ABS | IR3_REG_NEGATE) in flags.  If flags is NULL,
- * then disallow eliminating copies which would require flag
- * propagation (for example, we cannot propagate abs/neg into
- * an output).
+/* Handle special case of eliminating output mov, and similar cases where
+ * there isn't a normal "consuming" instruction.  In this case we cannot
+ * collapse flags (ie. output mov from const, or w/ abs/neg flags, cannot
+ * be eliminated)
  */
 static struct ir3_instruction *
-instr_cp(struct ir3_instruction *instr, unsigned *flags)
+eliminate_output_mov(struct ir3_instruction *instr)
 {
-       struct ir3_register *reg;
-
-       if (is_eligible_mov(instr, !!flags)) {
+       if (is_eligible_mov(instr, false)) {
                struct ir3_register *reg = instr->regs[1];
-               struct ir3_instruction *src_instr = ssa(reg);
-               if (flags)
-                       combine_flags(flags, reg->flags);
-               return instr_cp(src_instr, flags);
+               if (!(reg->flags & IR3_REG_ARRAY)) {
+                       struct ir3_instruction *src_instr = ssa(reg);
+                       debug_assert(src_instr);
+                       return src_instr;
+               }
        }
+       return instr;
+}
+
+/**
+ * Find instruction src's which are mov's that can be collapsed, replacing
+ * the mov dst with the mov src
+ */
+static void
+instr_cp(struct ir3_cp_ctx *ctx, struct ir3_instruction *instr)
+{
+       struct ir3_register *reg;
+
+       if (instr->regs_count == 0)
+               return;
 
-       /* Check termination condition before walking children (rather
-        * than before checking eligible-mov).  A mov instruction may
-        * appear as ssa-src for multiple other instructions, and we
-        * want to consider it for removal for each, rather than just
-        * the first one.  (But regardless of how many places it shows
-        * up as a src, we only need to recursively walk the children
-        * once.)
-        */
        if (ir3_instr_check_mark(instr))
-               return instr;
+               return;
 
        /* walk down the graph from each src: */
        foreach_src_n(reg, n, instr) {
-               if (!(reg->flags & IR3_REG_SSA))
+               struct ir3_instruction *src = ssa(reg);
+
+               if (!src)
+                       continue;
+
+               instr_cp(ctx, src);
+
+               /* TODO non-indirect access we could figure out which register
+                * we actually want and allow cp..
+                */
+               if (reg->flags & IR3_REG_ARRAY)
                        continue;
 
-               reg_cp(instr, reg, n);
+               reg_cp(ctx, instr, reg, n);
        }
 
-       if (instr->address)
-               ir3_instr_set_address(instr, instr_cp(instr->address, NULL));
+       if (instr->regs[0]->flags & IR3_REG_ARRAY) {
+               struct ir3_instruction *src = ssa(instr->regs[0]);
+               if (src)
+                       instr_cp(ctx, src);
+       }
 
-       return instr;
+       if (instr->address) {
+               instr_cp(ctx, instr->address);
+               ir3_instr_set_address(instr, eliminate_output_mov(instr->address));
+       }
+
+       /* we can end up with extra cmps.s from frontend, which uses a
+        *
+        *    cmps.s p0.x, cond, 0
+        *
+        * as a way to mov into the predicate register.  But frequently 'cond'
+        * is itself a cmps.s/cmps.f/cmps.u.  So detect this special case and
+        * just re-write the instruction writing predicate register to get rid
+        * of the double cmps.
+        */
+       if ((instr->opc == OPC_CMPS_S) &&
+                       (instr->regs[0]->num == regid(REG_P0, 0)) &&
+                       ssa(instr->regs[1]) &&
+                       (instr->regs[2]->flags & IR3_REG_IMMED) &&
+                       (instr->regs[2]->iim_val == 0)) {
+               struct ir3_instruction *cond = ssa(instr->regs[1]);
+               switch (cond->opc) {
+               case OPC_CMPS_S:
+               case OPC_CMPS_F:
+               case OPC_CMPS_U:
+                       instr->opc   = cond->opc;
+                       instr->flags = cond->flags;
+                       instr->cat2  = cond->cat2;
+                       instr->address = cond->address;
+                       instr->regs[1] = cond->regs[1];
+                       instr->regs[2] = cond->regs[2];
+                       break;
+               default:
+                       break;
+               }
+       }
 }
 
 void
-ir3_cp(struct ir3 *ir)
+ir3_cp(struct ir3 *ir, struct ir3_shader_variant *so)
 {
+       struct ir3_cp_ctx ctx = {
+                       .shader = ir,
+                       .so = so,
+       };
+
        ir3_clear_mark(ir);
 
        for (unsigned i = 0; i < ir->noutputs; i++) {
                if (ir->outputs[i]) {
-                       struct ir3_instruction *out =
-                                       instr_cp(ir->outputs[i], NULL);
-
-                       ir->outputs[i] = out;
+                       instr_cp(&ctx, ir->outputs[i]);
+                       ir->outputs[i] = eliminate_output_mov(ir->outputs[i]);
                }
        }
 
        list_for_each_entry (struct ir3_block, block, &ir->block_list, node) {
-               if (block->condition)
-                       block->condition = instr_cp(block->condition, NULL);
+               if (block->condition) {
+                       instr_cp(&ctx, block->condition);
+                       block->condition = eliminate_output_mov(block->condition);
+               }
+
+               for (unsigned i = 0; i < block->keeps_count; i++) {
+                       instr_cp(&ctx, block->keeps[i]);
+                       block->keeps[i] = eliminate_output_mov(block->keeps[i]);
+               }
        }
 }