Mesa (master): freedreno/ir3: fold const conversion into consumer

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Module: Mesa
Branch: master
Commit: 3eca6d9ce14abfc542031248be6a53c31cd113f9
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=3eca6d9ce14abfc542031248be6a53c31cd113f9

Author: Rob Clark <robdclark at chromium.org>
Date:   Thu Jun 20 16:31:00 2019 +0000

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 at chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3737>

---

 src/freedreno/ir3/ir3.h    | 19 +++++++++++++++++++
 src/freedreno/ir3/ir3_cp.c |  2 +-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/freedreno/ir3/ir3.h b/src/freedreno/ir3/ir3.h
index 6c286dcd7dd..fbe28ac3cc1 100644
--- 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 28c9f82f3ae..b7fb86ec791 100644
--- 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: */