/* XXX: need to clean this up so we get the typecasting right more naturally */
-/* LOOP FIXME 1
- * In bld_store_loop_var, only replace values that belong to the TGSI register
- * written.
- * For TGSI MOV, we only associate the source value with the value tracker of
- * the destination, instead of generating an actual MOV.
- *
- * Possible solution: generate PHI functions in loop headers in advance.
- */
-/* LOOP FIXME 2:
- * In fetch_by_bb, when going back through a break-block, we miss all of the
- * definitions from inside the loop.
- */
-
#include <unistd.h>
#include "nv50_context.h"
stk->body[stk->size++] = val;
}
+static INLINE boolean
+bld_vals_del_val(struct bld_value_stack *stk, struct nv_value *val)
+{
+ unsigned i;
+
+ for (i = stk->size - 1; i >= 0; --i)
+ if (stk->body[i] == val)
+ break;
+ if (i < 0)
+ return FALSE;
+
+ if (i != stk->size - 1)
+ stk->body[i] = stk->body[stk->size - 1];
+
+ --stk->size; /* XXX: old size in REALLOC */
+ return TRUE;
+}
+
static INLINE void
bld_vals_push(struct bld_value_stack *stk)
{
struct bld_value_stack pvs[BLD_MAX_PREDS][4]; /* TGSI_FILE_PREDICATE */
struct bld_value_stack ovs[PIPE_MAX_SHADER_OUTPUTS][4];
- uint32_t outputs_written[PIPE_MAX_SHADER_OUTPUTS / 32];
+ uint32_t outputs_written[(PIPE_MAX_SHADER_OUTPUTS + 31) / 32];
struct nv_value *frgcrd[4];
struct nv_value *sysval[4];
uint num_immds;
};
+static INLINE ubyte
+bld_stack_file(struct bld_context *bld, struct bld_value_stack *stk)
+{
+ if (stk < &bld->avs[0][0])
+ return NV_FILE_GPR;
+ else
+ if (stk < &bld->pvs[0][0])
+ return NV_FILE_ADDR;
+ else
+ if (stk < &bld->ovs[0][0])
+ return NV_FILE_FLAGS;
+ else
+ return NV_FILE_OUT;
+}
+
static INLINE struct nv_value *
bld_fetch(struct bld_context *bld, struct bld_value_stack *stk, int i, int c)
{
return stk[i * 4 + c].top;
}
-static void
-bld_store_loop_var(struct bld_context *, struct bld_value_stack *);
+static struct nv_value *
+bld_loop_phi(struct bld_context *, struct bld_value_stack *, struct nv_value *);
+/* If a variable is defined in a loop without prior use, we don't need
+ * a phi in the loop header to account for backwards flow.
+ *
+ * However, if this variable is then also used outside the loop, we do
+ * need a phi after all. But we must not use this phi's def inside the
+ * loop, so we can eliminate the phi if it is unused later.
+ */
static INLINE void
bld_store(struct bld_context *bld, struct bld_value_stack *stk, int i, int c,
struct nv_value *val)
{
- bld_store_loop_var(bld, &stk[i * 4 + c]);
+ const uint16_t m = 1 << bld->loop_lvl;
+
+ stk = &stk[i * 4 + c];
- stk[i * 4 + c].top = val;
+ if (bld->loop_lvl && !(m & (stk->loop_def | stk->loop_use)))
+ bld_loop_phi(bld, stk, val);
+
+ stk->top = val;
+ stk->loop_def |= 1 << bld->loop_lvl;
}
static INLINE void
long i = (stk - &bld->tvs[0][0]) / 4;
long c = (stk - &bld->tvs[0][0]) & 3;
+ if (c == 3)
+ c = -1;
+
debug_printf("WARNING: TEMP[%li].%c %s used uninitialized in BB:%i\n",
i, (int)('x' + c), kind ? "may be" : "is", b->id);
}
static INLINE struct nv_value *
bld_load_imm_u32(struct bld_context *bld, uint32_t u);
+static INLINE struct nv_value *
+bld_undef(struct bld_context *bld, ubyte file)
+{
+ struct nv_instruction *nvi = new_instruction(bld->pc, NV_OP_UNDEF);
+
+ return bld_def(nvi, 0, new_value(bld->pc, file, NV_TYPE_U32));
+}
+
static struct nv_value *
bld_phi(struct bld_context *bld, struct nv_basic_block *b,
struct bld_value_stack *stack)
if (in->num_in == 1) {
in = in->in[0];
} else {
- if (!nvbb_reachable_by(in->in[0], vals[0]->insn->bb, b)) {
+ if (!nvbb_reachable_by(in->in[0], vals[0]->insn->bb, b))
in = in->in[0];
- break;
- }
- if (!nvbb_reachable_by(in->in[1], vals[0]->insn->bb, b)) {
+ else
+ if (!nvbb_reachable_by(in->in[1], vals[0]->insn->bb, b))
in = in->in[1];
- break;
- }
- in = in->in[0];
+ else
+ in = in->in[0];
}
}
bld->pc->current_block = in;
/* should make this a no-op */
- bld_vals_push_val(stack, bld_load_imm_u32(bld, 0));
+ bld_vals_push_val(stack, bld_undef(bld, vals[0]->reg.file));
continue;
}
return phi->def[0];
}
+static struct nv_value *
+bld_loop_phi(struct bld_context *bld, struct bld_value_stack *stack,
+ struct nv_value *def)
+{
+ struct nv_basic_block *bb = bld->pc->current_block;
+ struct nv_instruction *phi;
+ struct nv_value *val;
+
+ val = bld_phi(bld, bld->pc->current_block, stack);
+ if (!val) {
+ bld->pc->current_block = bld->loop_bb[bld->loop_lvl - 1]->in[0];
+
+ val = bld_undef(bld, bld_stack_file(bld, stack));
+ }
+
+ bld->pc->current_block = bld->loop_bb[bld->loop_lvl - 1];
+
+ phi = new_instruction(bld->pc, NV_OP_PHI);
+
+ bld_def(phi, 0, new_value_like(bld->pc, val));
+ if (!def)
+ def = phi->def[0];
+
+ bld_vals_push_val(stack, phi->def[0]);
+
+ phi->target = (struct nv_basic_block *)stack; /* cheat */
+
+ nv_reference(bld->pc, &phi->src[0], val);
+ nv_reference(bld->pc, &phi->src[1], def);
+
+ bld->pc->current_block = bb;
+
+ return phi->def[0];
+}
+
static INLINE struct nv_value *
bld_fetch_global(struct bld_context *bld, struct bld_value_stack *stack)
{
- stack->loop_use |= 1 << bld->loop_lvl;
+ const uint16_t m = 1 << bld->loop_lvl;
+ const uint16_t use = stack->loop_use;
+
+ stack->loop_use |= m;
+
+ /* If neither used nor def'd inside the loop, build a phi in foresight,
+ * so we don't have to replace stuff later on, which requires tracking.
+ */
+ if (bld->loop_lvl && !((use | stack->loop_def) & m))
+ return bld_loop_phi(bld, stack, NULL);
+
return bld_phi(bld, bld->pc->current_block, stack);
}
bld_replace_value(struct nv_pc *, struct nv_basic_block *, struct nv_value *,
struct nv_value *);
-/* When setting a variable inside a loop, and we have used it before in the
- * loop, we need to insert a phi function in the loop header.
+/* Replace the source of the phi in the loop header by the last assignment,
+ * or eliminate the phi function if there is no assignment inside the loop.
+ *
+ * Redundancy situation 1 - (used) but (not redefined) value:
+ * %3 = phi %0, %3 = %3 is used
+ * %3 = phi %0, %4 = is new definition
+ *
+ * Redundancy situation 2 - (not used) but (redefined) value:
+ * %3 = phi %0, %2 = %2 is used, %3 could be used outside, deleted by DCE
*/
static void
-bld_store_loop_var(struct bld_context *bld, struct bld_value_stack *stk)
+bld_loop_end(struct bld_context *bld, struct nv_basic_block *bb)
{
- struct nv_basic_block *bb;
- struct nv_instruction *phi;
+ struct nv_instruction *phi, *next;
struct nv_value *val;
- int ll;
- uint16_t loop_def = stk->loop_def;
-
- if (!(ll = bld->loop_lvl))
- return;
- stk->loop_def |= 1 << ll;
-
- if ((~stk->loop_use | loop_def) & (1 << ll))
- return;
-
-#if 0
- debug_printf("TEMP[%li].%c used before loop redef (def=%x/use=%x)\n",
- (stk - &bld->tvs[0][0]) / 4,
- (int)('x' + ((stk - &bld->tvs[0][0]) & 3)),
- loop_def, stk->loop_use);
-#endif
+ struct bld_value_stack *stk;
+ int s;
- stk->loop_def |= 1 << ll;
+ for (phi = bb->phi; phi && phi->opcode == NV_OP_PHI; phi = next) {
+ next = phi->next;
- assert(bld->loop_bb[ll - 1]->num_in == 1);
-
- /* get last assignment from outside this loop, could be from bld_phi */
- val = stk->body[stk->size - 1];
-
- /* create the phi in the loop entry block */
-
- bb = bld->pc->current_block;
- bld->pc->current_block = bld->loop_bb[ll - 1];
-
- phi = new_instruction(bld->pc, NV_OP_PHI);
+ stk = (struct bld_value_stack *)phi->target;
+ phi->target = NULL;
- bld_def(phi, 0, new_value(bld->pc, val->reg.file, val->reg.type));
+ val = bld_fetch_global(bld, stk);
- bld->pc->pass_seq++;
- bld_replace_value(bld->pc, bld->loop_bb[ll - 1], val, phi->def[0]);
+ nv_reference(bld->pc, &phi->src[1], val);
- assert(!stk->top);
- bld_vals_push_val(stk, phi->def[0]);
+ s = -1;
+ if (phi->src[0]->value == phi->def[0] ||
+ phi->src[0]->value == phi->src[1]->value)
+ s = 1;
+ else
+ if (phi->src[1]->value == phi->def[0])
+ s = 0;
- phi->target = (struct nv_basic_block *)stk; /* cheat */
+ if (s >= 0) {
+ bld_vals_del_val(stk, phi->def[0]);
- nv_reference(bld->pc, &phi->src[0], val);
- nv_reference(bld->pc, &phi->src[1], phi->def[0]);
+ ++bld->pc->pass_seq;
+ bld_replace_value(bld->pc, bb, phi->def[0], phi->src[s]->value);
- bld->pc->current_block = bb;
-}
-
-static void
-bld_loop_end(struct bld_context *bld, struct nv_basic_block *bb)
-{
- struct nv_instruction *phi;
- struct nv_value *val;
-
- for (phi = bb->phi; phi && phi->opcode == NV_OP_PHI; phi = phi->next) {
- val = bld_fetch_global(bld, (struct bld_value_stack *)phi->target);
- nv_reference(bld->pc, &phi->src[1], val);
- phi->target = NULL;
+ nv_nvi_delete(phi);
+ }
}
}
static struct nv_value *
bld_insn_2(struct bld_context *bld, uint opcode,
- struct nv_value *src0, struct nv_value *src1)
+ struct nv_value *src0, struct nv_value *src1)
{
struct nv_instruction *insn = new_instruction(bld->pc, opcode);
static struct nv_value *
bld_insn_3(struct bld_context *bld, uint opcode,
- struct nv_value *src0, struct nv_value *src1,
- struct nv_value *src2)
+ struct nv_value *src0, struct nv_value *src1,
+ struct nv_value *src2)
{
struct nv_instruction *insn = new_instruction(bld->pc, opcode);
projects / mesa.git / commitdiff