freedreno/ir3: reads/writes to unrelated arrays are not dependent

Signed-off-by: Rob Clark <robdclark@gmail.com>

diff --git a/src/freedreno/ir3/ir3_sched.c b/src/freedreno/ir3/ir3_sched.c
index 94a7fed4c95ecc9d5b414d3c597d0ca9a5436d4a..dd9567764f76cce5508573daa3d9bb45af1f5e20 100644 (file)
--- a/src/freedreno/ir3/ir3_sched.c
+++ b/src/freedreno/ir3/ir3_sched.c
@@ -807,6 +807,20 @@ int ir3_sched(struct ir3 *ir)
        return 0;
 }
 
+static unsigned
+get_array_id(struct ir3_instruction *instr)
+{
+       /* The expectation is that there is only a single array
+        * src or dst, ir3_cp should enforce this.
+        */
+
+       for (unsigned i = 0; i < instr->regs_count; i++)
+               if (instr->regs[i]->flags & IR3_REG_ARRAY)
+                       return instr->regs[i]->array.id;
+
+       unreachable("this was unexpected");
+}
+
 /* does instruction 'prior' need to be scheduled before 'instr'? */
 static bool
 depends_on(struct ir3_instruction *instr, struct ir3_instruction *prior)
@@ -819,7 +833,22 @@ depends_on(struct ir3_instruction *instr, struct ir3_instruction *prior)
        if (((instr->barrier_class & IR3_BARRIER_EVERYTHING) && prior->barrier_class) ||
                        ((prior->barrier_class & IR3_BARRIER_EVERYTHING) && instr->barrier_class))
                return true;
-       return !!(instr->barrier_class & prior->barrier_conflict);
+
+       if (instr->barrier_class & prior->barrier_conflict) {
+               if (!(instr->barrier_class & ~(IR3_BARRIER_ARRAY_R | IR3_BARRIER_ARRAY_W))) {
+                       /* if only array barrier, then we can further limit false-deps
+                        * by considering the array-id, ie reads/writes to different
+                        * arrays do not depend on each other (no aliasing)
+                        */
+                       if (get_array_id(instr) != get_array_id(prior)) {
+                               return false;
+                       }
+               }
+
+               return true;
+       }
+
+       return false;
 }
 
 static void