freedreno/ir3: fold const conversion into consumer

A sequence like:

  (nop3)cov.f32f16 hr0.x, c0.x
  mul.f hr4.y, hr1.z, hr0.x

can be turned into:

  mul.f hr4.y, hr1.z, hc0.x

Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3737>

diff --git a/src/freedreno/ir3/ir3.h b/src/freedreno/ir3/ir3.h
index 6c286dcd7dd16a496af34481a5e29849c1bd9f55..fbe28ac3cc17584652541a5099d6dd8edc0ac5d0 100644 (file)
--- a/src/freedreno/ir3/ir3.h
+++ b/src/freedreno/ir3/ir3.h
@@ -695,6 +695,25 @@ static inline bool is_same_type_mov(struct ir3_instruction *instr)
        return true;
 }
 
+/* A move from const, which changes size but not type, can also be
+ * folded into dest instruction in some cases.
+ */
+static inline bool is_const_mov(struct ir3_instruction *instr)
+{
+       if (instr->opc != OPC_MOV)
+               return false;
+
+       if (!(instr->regs[1]->flags & IR3_REG_CONST))
+               return false;
+
+       type_t src_type = instr->cat1.src_type;
+       type_t dst_type = instr->cat1.dst_type;
+
+       return (type_float(src_type) && type_float(dst_type)) ||
+               (type_uint(src_type) && type_uint(dst_type)) ||
+               (type_sint(src_type) && type_sint(dst_type));
+}
+
 static inline bool is_alu(struct ir3_instruction *instr)
 {
        return (1 <= opc_cat(instr->opc)) && (opc_cat(instr->opc) <= 3);

diff --git a/src/freedreno/ir3/ir3_cp.c b/src/freedreno/ir3/ir3_cp.c
index 28c9f82f3ae3ee90f7216d5b57cca4cd2cdb32b4..b7fb86ec791ab3c944bf023140088050edce2e74 100644 (file)
--- a/src/freedreno/ir3/ir3_cp.c
+++ b/src/freedreno/ir3/ir3_cp.c
@@ -463,7 +463,7 @@ reg_cp(struct ir3_cp_ctx *ctx, struct ir3_instruction *instr,
 
                        return true;
                }
-       } else if (is_same_type_mov(src) &&
+       } else if ((is_same_type_mov(src) || is_const_mov(src)) &&
                        /* cannot collapse const/immed/etc into meta instrs: */
                        !is_meta(instr)) {
                /* immed/const/etc cases, which require some special handling: */