agx: Switch to dynamic allocation of srcs/dests

So we can handle parallel copies later.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18804>

src/asahi/compiler/agx_builder.h.py

@@ -27,10 +27,19 @@ template = """/*
 #include "agx_compiler.h"
 
 static inline agx_instr *
-agx_alloc_instr(agx_builder *b, enum agx_opcode op)
+agx_alloc_instr(agx_builder *b, enum agx_opcode op, uint8_t nr_dests, uint8_t nr_srcs)
 {
-   agx_instr *I = rzalloc(b->shader, agx_instr);
+   size_t size = sizeof(agx_instr);
+   size += sizeof(agx_index) * nr_dests;
+   size += sizeof(agx_index) * nr_srcs;
+
+   agx_instr *I = (agx_instr *) rzalloc_size(b->shader, size);
+   I->dest = (agx_index *) (I + 1);
+   I->src = I->dest + nr_dests;
+
    I->op = op;
+   I->nr_dests = nr_dests;
+   I->nr_srcs = nr_srcs;
    return I;
 }
 
@@ -41,11 +50,17 @@ agx_alloc_instr(agx_builder *b, enum agx_opcode op)
    srcs = op.srcs
    imms = op.imms
    suffix = "_to" if dests > 0 else ""
+   nr_dests = "nr_dests" if op.variable_dests else str(dests)
+   nr_srcs = "nr_srcs" if op.variable_srcs else str(srcs)
 %>
 
 static inline agx_instr *
 agx_${opcode}${suffix}(agx_builder *b
 
+% if op.variable_dests:
+   , unsigned nr_dests
+% endif
+
 % for dest in range(dests):
    , agx_index dst${dest}
 % endfor
@@ -63,23 +78,15 @@ agx_${opcode}${suffix}(agx_builder *b
 % endfor
 
 ) {
-   agx_instr *I = agx_alloc_instr(b, AGX_OPCODE_${opcode.upper()});
+   agx_instr *I = agx_alloc_instr(b, AGX_OPCODE_${opcode.upper()}, ${nr_dests}, ${nr_srcs});
 
 % for dest in range(dests):
    I->dest[${dest}] = dst${dest};
 % endfor
 
-% if op.variable_srcs:
-   I->src = ralloc_array(I, agx_index, nr_srcs);
-   I->nr_srcs = nr_srcs;
-% elif srcs > 0:
-   I->src = ralloc_array(I, agx_index, ${srcs});
-   I->nr_srcs = ${srcs};
-
 % for src in range(srcs):
    I->src[${src}] = src${src};
 % endfor
-% endif
 
 % for imm in imms:
    I->${imm.name} = ${imm.name};
@@ -89,7 +96,7 @@ agx_${opcode}${suffix}(agx_builder *b
    return I;
 }
 
-% if dests == 1 and not op.variable_srcs:
+% if dests == 1 and not op.variable_srcs and not op.variable_dests:
 static inline agx_index
 agx_${opcode}(agx_builder *b
 

src/asahi/compiler/agx_compile.c

@@ -1207,7 +1207,8 @@ agx_emit_jump(agx_builder *b, nir_jump_instr *instr)
 static void
 agx_emit_phi(agx_builder *b, nir_phi_instr *instr)
 {
-   agx_instr *I = agx_phi_to(b, agx_dest_index(&instr->dest));
+   agx_instr *I = agx_phi_to(b, agx_dest_index(&instr->dest),
+                             exec_list_length(&instr->srcs));
 
    /* Deferred */
    I->phi = instr;
@@ -1230,9 +1231,6 @@ agx_emit_phi_deferred(agx_context *ctx, agx_block *block, agx_instr *I)
    /* Guaranteed by lower_phis_to_scalar */
    assert(phi->dest.ssa.num_components == 1);
 
-   I->nr_srcs = exec_list_length(&phi->srcs);
-   I->src = rzalloc_array(I, agx_index, I->nr_srcs);
-
    nir_foreach_phi_src(src, phi) {
       agx_block *pred = agx_from_nir_block(ctx, src->pred);
       unsigned i = agx_predecessor_index(block, pred);

src/asahi/compiler/agx_compiler.h

@@ -288,12 +288,13 @@ typedef struct {
       nir_phi_instr *phi;
    };
 
+   /* Data flow */
+   agx_index *dest;
+
    enum agx_opcode op;
 
-   /* Data flow */
-   agx_index dest[AGX_MAX_DESTS];
-
-   unsigned nr_srcs;
+   uint8_t nr_dests;
+   uint8_t nr_srcs;
 
    union {
       uint32_t imm;
@@ -534,7 +535,7 @@ agx_vec_for_intr(agx_context *ctx, nir_intrinsic_instr *instr)
    for (unsigned v = 0; v < ins->nr_srcs; ++v)
 
 #define agx_foreach_dest(ins, v) \
-   for (unsigned v = 0; v < ARRAY_SIZE(ins->dest); ++v)
+   for (unsigned v = 0; v < ins->nr_dests; ++v)
 
 /* Phis only come at the start so we stop as soon as we hit a non-phi */
 #define agx_foreach_phi_in_block(block, v) \

src/asahi/compiler/agx_lower_pseudo.c

@@ -25,40 +25,38 @@
 #include "agx_builder.h"
 
 /* Lower pseudo instructions created during optimization. */
-
-static void
-agx_lower_to_unary_bitop(agx_instr *I, enum agx_bitop_table table)
+static agx_instr *
+lower(agx_builder *b, agx_instr *I)
 {
-   I->op = AGX_OPCODE_BITOP;
-   I->truth_table = table;
+   switch (I->op) {
 
-   /* Allocate extra source */
-   I->src = reralloc_array_size(I, I->src, sizeof(agx_index), I->nr_srcs++);
-   I->src[1] = agx_zero();
+   /* Various instructions are implemented as bitwise truth tables */
+   case AGX_OPCODE_MOV:
+      return agx_bitop_to(b, I->dest[0], I->src[0], agx_zero(), AGX_BITOP_MOV);
+
+   case AGX_OPCODE_NOT:
+      return agx_bitop_to(b, I->dest[0], I->src[0], agx_zero(), AGX_BITOP_NOT);
+
+   case AGX_OPCODE_AND:
+      return agx_bitop_to(b, I->dest[0], I->src[0], I->src[1], AGX_BITOP_AND);
+
+   case AGX_OPCODE_XOR:
+      return agx_bitop_to(b, I->dest[0], I->src[0], I->src[1], AGX_BITOP_XOR);
+
+   case AGX_OPCODE_OR:
+      return agx_bitop_to(b, I->dest[0], I->src[0], I->src[1], AGX_BITOP_OR);
+
+   default: return NULL;
    }
-
-static void
-agx_lower_to_binary_bitop(agx_instr *I, enum agx_bitop_table table)
-{
-   I->op = AGX_OPCODE_BITOP;
-   I->truth_table = table;
 }
 
 void
 agx_lower_pseudo(agx_context *ctx)
 {
-   agx_foreach_instr_global(ctx, I) {
-      switch (I->op) {
+   agx_foreach_instr_global_safe(ctx, I) {
+      agx_builder b = agx_init_builder(ctx, agx_before_instr(I));
 
-      /* Various instructions are implemented as bitwise truth tables */
-      case AGX_OPCODE_MOV: agx_lower_to_unary_bitop(I, AGX_BITOP_MOV); break;
-      case AGX_OPCODE_NOT: agx_lower_to_unary_bitop(I, AGX_BITOP_NOT); break;
-      case AGX_OPCODE_AND: agx_lower_to_binary_bitop(I, AGX_BITOP_AND); break;
-      case AGX_OPCODE_XOR: agx_lower_to_binary_bitop(I, AGX_BITOP_XOR); break;
-      case AGX_OPCODE_OR:  agx_lower_to_binary_bitop(I, AGX_BITOP_OR); break;
-
-      default:
-         break;
-      }
+      if (lower(&b, I))
+         agx_remove_instruction(I);
    }
 }

src/asahi/compiler/agx_opcodes.py

@@ -267,9 +267,6 @@ op("logical_end", _, dests = 0, srcs = 0, can_eliminate = False)
 
 op("combine", _, srcs = VARIABLE)
 op("split", _, srcs = 1, dests = 4)
-
-# Phis are special-cased in the IR as they (uniquely) can take an unbounded
-# number of source.
-op("phi", _, srcs = 0)
+op("phi", _, srcs = VARIABLE)
 
 op("unit_test", _, dests = 0, srcs = 1, can_eliminate = False)

src/asahi/compiler/test/agx_test.h

@@ -58,7 +58,7 @@ agx_test_builder(void *memctx)
 static inline bool
 agx_instr_equal(agx_instr *A, agx_instr *B)
 {
-   unsigned pointers = sizeof(struct list_head) + sizeof(agx_index *);
+   unsigned pointers = sizeof(struct list_head) + sizeof(agx_index *) * 2;
 
    if (A->nr_srcs != B->nr_srcs)
       return false;
@@ -66,6 +66,12 @@ agx_instr_equal(agx_instr *A, agx_instr *B)
    if (memcmp(A->src, B->src, A->nr_srcs * sizeof(agx_index)))
       return false;
 
+   if (A->nr_dests != B->nr_dests)
+      return false;
+
+   if (memcmp(A->dest, B->dest, A->nr_dests * sizeof(agx_index)))
+      return false;
+
    return memcmp((uint8_t *) A    + pointers,
                  (uint8_t *) B    + pointers,
                  sizeof(agx_instr) - pointers) == 0;