freedreno/ir3/ra: fix array conflicts for split/merged

Properly handle the difference between split and merged register file
when determining where arrays can fit without conflicting with other
arrays or pre-colored instructions.

1) if not mergedregs, only consider other things with same precision
   as potentially conflicting
2) if mergedregs, calculate everything in therms of half-regs and
   convert back to fullregs in the end

Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5957>

diff --git a/src/freedreno/ir3/ir3_ra.c b/src/freedreno/ir3/ir3_ra.c
index 156299fc18e4999dc8eb139d160cf5e4381f0279..abf665288fd240ca25ce6bfab73b562fdef02222 100644 (file)
--- a/src/freedreno/ir3/ir3_ra.c
+++ b/src/freedreno/ir3/ir3_ra.c
@@ -115,15 +115,6 @@ intersects(unsigned a_start, unsigned a_end, unsigned b_start, unsigned b_end)
        return !((a_start >= b_end) || (b_start >= a_end));
 }
 
-static unsigned
-reg_size_for_array(struct ir3_array *arr)
-{
-       if (arr->half)
-               return DIV_ROUND_UP(arr->length, 2);
-
-       return arr->length;
-}
-
 static bool
 instr_before(struct ir3_instruction *a, struct ir3_instruction *b)
 {
@@ -1246,6 +1237,15 @@ static void
 assign_arr_base(struct ir3_ra_ctx *ctx, struct ir3_array *arr,
                struct ir3_instruction **precolor, unsigned nprecolor)
 {
+       /* In the mergedregs case, we convert full precision arrays
+        * to their effective half-precision base, and find conflicts
+        * amongst all other arrays/inputs.
+        *
+        * In the splitregs case (halfreg file and fullreg file do
+        * not conflict), we ignore arrays and other pre-colors that
+        * are not the same precision.
+        */
+       bool mergedregs = ctx->v->mergedregs;
        unsigned base = 0;
 
        /* figure out what else we conflict with which has already
@@ -1255,14 +1255,34 @@ retry:
        foreach_array (arr2, &ctx->ir->array_list) {
                if (arr2 == arr)
                        break;
-               if (arr2->end_ip == 0)
+               ra_assert(ctx, arr2->start_ip <= arr2->end_ip);
+
+               unsigned base2 = arr2->reg;
+               unsigned len2  = arr2->length;
+               unsigned len   = arr->length;
+
+               if (mergedregs) {
+                       /* convert into half-reg space: */
+                       if (!arr2->half) {
+                               base2 *= 2;
+                               len2  *= 2;
+                       }
+                       if (!arr->half) {
+                               len   *= 2;
+                       }
+               } else if (arr2->half != arr->half) {
+                       /* for split-register-file mode, we only conflict with
+                        * other arrays of same precision:
+                        */
                        continue;
+               }
+
                /* if it intersects with liverange AND register range.. */
                if (intersects(arr->start_ip, arr->end_ip,
                                arr2->start_ip, arr2->end_ip) &&
-                       intersects(base, base + reg_size_for_array(arr),
-                               arr2->reg, arr2->reg + reg_size_for_array(arr2))) {
-                       base = MAX2(base, arr2->reg + reg_size_for_array(arr2));
+                       intersects(base, base + len,
+                               base2, base2 + len2)) {
+                       base = MAX2(base, base2 + len2);
                        goto retry;
                }
        }
@@ -1280,21 +1300,44 @@ retry:
                if (id->off > 0)
                        continue;
 
-               unsigned name = ra_name(ctx, id);
-               unsigned regid = instr->regs[0]->num;
+               unsigned name   = ra_name(ctx, id);
+               unsigned regid  = instr->regs[0]->num;
+               unsigned reglen = class_sizes[id->cls];
+               unsigned len    = arr->length;
+
+               if (mergedregs) {
+                       /* convert into half-reg space: */
+                       if (!is_half(instr)) {
+                               regid  *= 2;
+                               reglen *= 2;
+                       }
+                       if (!arr->half) {
+                               len   *= 2;
+                       }
+               } else if (is_half(instr) != arr->half) {
+                       /* for split-register-file mode, we only conflict with
+                        * other arrays of same precision:
+                        */
+                       continue;
+               }
 
                /* Check if array intersects with liverange AND register
                 * range of the input:
                 */
                if (intersects(arr->start_ip, arr->end_ip,
                                                ctx->def[name], ctx->use[name]) &&
-                               intersects(base, base + reg_size_for_array(arr),
-                                               regid, regid + class_sizes[id->cls])) {
-                       base = MAX2(base, regid + class_sizes[id->cls]);
+                               intersects(base, base + len,
+                                               regid, regid + reglen)) {
+                       base = MAX2(base, regid + reglen);
                        goto retry;
                }
        }
 
+       /* convert back from half-reg space to fullreg space: */
+       if (mergedregs && !arr->half) {
+               base = DIV_ROUND_UP(base, 2);
+       }
+
        arr->reg = base;
 }