Mesa (master): ir3: Use the new NIR lowering pass for integer multiplication

[GitLab Mirror]

Module: Mesa
Branch: master
Commit: c02ffd2700cc71b08453c2c609b2057681330b4a
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=c02ffd2700cc71b08453c2c609b2057681330b4a

Author: Eduardo Lima Mitev <elima at igalia.com>
Date:   Mon May 13 00:33:57 2019 +0200

ir3: Use the new NIR lowering pass for integer multiplication

Shader-db stats courtesy of Eric Anholt:

total instructions in shared programs: 6480215 -> 6475457 (-0.07%)
instructions in affected programs: 662105 -> 657347 (-0.72%)
helped: 1209
HURT: 13
total constlen in shared programs: 1432704 -> 1427769 (-0.34%)
constlen in affected programs: 100063 -> 95128 (-4.93%)
helped: 512
HURT: 0
total max_sun in shared programs: 875561 -> 873387 (-0.25%)
max_sun in affected programs: 46179 -> 44005 (-4.71%)
helped: 1087
HURT: 0

Reviewed-by: Eric Anholt <eric at anholt.net>

---

 src/freedreno/ir3/ir3_compiler_nir.c | 17 -----------------
 src/freedreno/ir3/ir3_context.c      | 16 ++++++++++++++++
 2 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/src/freedreno/ir3/ir3_compiler_nir.c b/src/freedreno/ir3/ir3_compiler_nir.c
index 1a75181a967..e453f33fb91 100644
--- a/src/freedreno/ir3/ir3_compiler_nir.c
+++ b/src/freedreno/ir3/ir3_compiler_nir.c
@@ -542,23 +542,6 @@ emit_alu(struct ir3_context *ctx, nir_alu_instr *alu)
 	case nir_op_umin:
 		dst[0] = ir3_MIN_U(b, src[0], 0, src[1], 0);
 		break;
-	case nir_op_imul:
-		if (bs[0] > 16 || bs[1] > 16) {
-			/*
-			 * dst = (al * bl) + (ah * bl << 16) + (al * bh << 16)
-			 *   mull.u tmp0, a, b           ; mul low, i.e. al * bl
-			 *   madsh.m16 tmp1, a, b, tmp0  ; mul-add shift high mix,
-			 *                               ; i.e. ah * bl << 16
-			 *   madsh.m16 dst, b, a, tmp1   ; i.e. al * bh << 16
-			 */
-			dst[0] = ir3_MADSH_M16(b, src[1], 0, src[0], 0,
-								   ir3_MADSH_M16(b, src[0], 0, src[1], 0,
-												 ir3_MULL_U(b, src[0], 0,
-															src[1], 0), 0), 0);
-		} else {
-			dst[0] = ir3_MUL_S(b, src[0], 0, src[1], 0);
-		}
-		break;
 	case nir_op_umul_low:
 		dst[0] = ir3_MULL_U(b, src[0], 0, src[1], 0);
 		break;
diff --git a/src/freedreno/ir3/ir3_context.c b/src/freedreno/ir3/ir3_context.c
index 99997427ec3..e572f33ef24 100644
--- a/src/freedreno/ir3/ir3_context.c
+++ b/src/freedreno/ir3/ir3_context.c
@@ -84,6 +84,22 @@ ir3_context_init(struct ir3_compiler *compiler,
 	 */
 	NIR_PASS_V(ctx->s, nir_lower_bool_to_int32);
 	NIR_PASS_V(ctx->s, nir_lower_locals_to_regs);
+
+	/* We want to lower nir_op_imul as late as possible, to catch also
+	 * those generated by earlier passes (e.g, nir_lower_locals_to_regs).
+	 * However, we want a final swing of a few passes to have a chance
+	 * at optimizing the result.
+	 */
+	bool progress;
+	NIR_PASS(progress, ctx->s, ir3_nir_lower_imul);
+	if (progress) {
+		NIR_PASS_V(ctx->s, nir_opt_algebraic);
+		NIR_PASS_V(ctx->s, nir_opt_copy_prop_vars);
+		NIR_PASS_V(ctx->s, nir_opt_dead_write_vars);
+		NIR_PASS_V(ctx->s, nir_opt_dce);
+		NIR_PASS_V(ctx->s, nir_opt_constant_folding);
+	}
+
 	NIR_PASS_V(ctx->s, nir_convert_from_ssa, true);
 
 	if (ir3_shader_debug & IR3_DBG_DISASM) {