ir3: Remove right and left copy prop restrictions

This is leftover from the old RA, and inhibits copy propagation
unnecessarily with the new RA.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9842>

diff --git a/src/freedreno/ir3/ir3.h b/src/freedreno/ir3/ir3.h
index c2733a0..5239ce9 100644 (file)
--- a/src/freedreno/ir3/ir3.h
+++ b/src/freedreno/ir3/ir3.h
@@ -379,33 +379,6 @@ struct ir3_instruction {
 
        int use_count;      /* currently just updated/used by cp */
 
-       /* Used during CP and RA stages.  For collect and shader inputs/
-        * outputs where we need a sequence of consecutive registers,
-        * keep track of each src instructions left (ie 'n-1') and right
-        * (ie 'n+1') neighbor.  The front-end must insert enough mov's
-        * to ensure that each instruction has at most one left and at
-        * most one right neighbor.  During the copy-propagation pass,
-        * we only remove mov's when we can preserve this constraint.
-        * And during the RA stage, we use the neighbor information to
-        * allocate a block of registers in one shot.
-        *
-        * TODO: maybe just add something like:
-        *   struct ir3_instruction_ref {
-        *       struct ir3_instruction *instr;
-        *       unsigned cnt;
-        *   }
-        *
-        * Or can we get away without the refcnt stuff?  It seems like
-        * it should be overkill..  the problem is if, potentially after
-        * already eliminating some mov's, if you have a single mov that
-        * needs to be grouped with it's neighbors in two different
-        * places (ex. shader output and a collect).
-        */
-       struct {
-               struct ir3_instruction *left, *right;
-               uint16_t left_cnt, right_cnt;
-       } cp;
-
        /* an instruction can reference at most one address register amongst
         * it's src/dst registers.  Beyond that, you need to insert mov's.
         *
@@ -458,38 +431,6 @@ struct ir3_instruction {
        int line;
 };
 
-static inline struct ir3_instruction *
-ir3_neighbor_first(struct ir3_instruction *instr)
-{
-       int cnt = 0;
-       while (instr->cp.left) {
-               instr = instr->cp.left;
-               if (++cnt > 0xffff) {
-                       debug_assert(0);
-                       break;
-               }
-       }
-       return instr;
-}
-
-static inline int ir3_neighbor_count(struct ir3_instruction *instr)
-{
-       int num = 1;
-
-       debug_assert(!instr->cp.left);
-
-       while (instr->cp.right) {
-               num++;
-               instr = instr->cp.right;
-               if (num > 0xffff) {
-                       debug_assert(0);
-                       break;
-               }
-       }
-
-       return num;
-}
-
 struct ir3 {
        struct ir3_compiler *compiler;
        gl_shader_stage type;

diff --git a/src/freedreno/ir3/ir3_context.c b/src/freedreno/ir3/ir3_context.c
index 0e58d3c..89137b8 100644 (file)
--- a/src/freedreno/ir3/ir3_context.c
+++ b/src/freedreno/ir3/ir3_context.c
@@ -358,8 +358,6 @@ void
 ir3_split_dest(struct ir3_block *block, struct ir3_instruction **dst,
                struct ir3_instruction *src, unsigned base, unsigned n)
 {
-       struct ir3_instruction *prev = NULL;
-
        if ((n == 1) && (src->regs[0]->wrmask == 0x1) &&
                /* setup_input needs ir3_split_dest to generate a SPLIT instruction */
                src->opc != OPC_META_INPUT) {
@@ -387,14 +385,6 @@ ir3_split_dest(struct ir3_block *block, struct ir3_instruction **dst,
                __ssa_src(split, src, flags);
                split->split.off = i + base;
 
-               if (prev) {
-                       split->cp.left = prev;
-                       split->cp.left_cnt++;
-                       prev->cp.right = split;
-                       prev->cp.right_cnt++;
-               }
-               prev = split;
-
                if (src->regs[0]->wrmask & (1 << (i + base)))
                        dst[j++] = split;
        }

diff --git a/src/freedreno/ir3/ir3_cp.c b/src/freedreno/ir3/ir3_cp.c
index e9899c1..2198310 100644 (file)
--- a/src/freedreno/ir3/ir3_cp.c
+++ b/src/freedreno/ir3/ir3_cp.c
@@ -79,22 +79,6 @@ static bool is_eligible_mov(struct ir3_instruction *instr,
                                        IR3_REG_SABS | IR3_REG_SNEG | IR3_REG_BNOT))
                                return false;
 
-               /* If src is coming from fanout/split (ie. one component of a
-                * texture fetch, etc) and we have constraints on swizzle of
-                * destination, then skip it.
-                *
-                * We could possibly do a bit better, and copy-propagation if
-                * we can CP all components that are being fanned out.
-                */
-               if (src_instr->opc == OPC_META_SPLIT) {
-                       if (!dst_instr)
-                               return false;
-                       if (dst_instr->opc == OPC_META_COLLECT)
-                               return false;
-                       if (dst_instr->cp.left || dst_instr->cp.right)
-                               return false;
-               }
-
                return true;
        }
        return false;

diff --git a/src/freedreno/ir3/ir3_dce.c b/src/freedreno/ir3/ir3_dce.c
index a877047..e405715 100644 (file)
--- a/src/freedreno/ir3/ir3_dce.c
+++ b/src/freedreno/ir3/ir3_dce.c
@@ -79,21 +79,6 @@ remove_unused_by_block(struct ir3_block *block)
                                 */
                                if (src && is_tex_or_prefetch(src) && (src->regs[0]->wrmask > 1)) {
                                        src->regs[0]->wrmask &= ~(1 << instr->split.off);
-
-                                       /* prune no-longer needed right-neighbors.  We could
-                                        * probably do the same for left-neighbors (ie. tex
-                                        * fetch that only need .yw components), but that
-                                        * makes RA a bit more confusing than it already is
-                                        */
-                                       struct ir3_instruction *n = instr;
-                                       while (n && n->cp.right)
-                                               n = n->cp.right;
-                                       while (n->flags & IR3_INSTR_UNUSED) {
-                                               n = n->cp.left;
-                                               if (!n)
-                                                       break;
-                                               n->cp.right = NULL;
-                                       }
                                }
                        }
 

diff --git a/src/freedreno/ir3/ir3_print.c b/src/freedreno/ir3/ir3_print.c
index 3646421..cc09965 100644 (file)
--- a/src/freedreno/ir3/ir3_print.c
+++ b/src/freedreno/ir3/ir3_print.c
@@ -298,20 +298,6 @@ print_instr(struct ir3_instruction *instr, int lvl)
                printf("]");
        }
 
-       if (instr->cp.left) {
-               printf(", left=_");
-               printf("[");
-               print_instr_name(instr->cp.left, false);
-               printf("]");
-       }
-
-       if (instr->cp.right) {
-               printf(", right=_");
-               printf("[");
-               print_instr_name(instr->cp.right, false);
-               printf("]");
-       }
-
        if (instr->opc == OPC_META_SPLIT) {
                printf(", off=%d", instr->split.off);
        } else if (instr->opc == OPC_META_TEX_PREFETCH) {