[Mesa-dev] [PATCH 9/9] ir3/compiler: Handle the new ir3 intrinsics for SSBO

Eduardo Lima Mitev elima at igalia.com
Wed Feb 13 21:29:56 UTC 2019


These intrinsics have the offset in dwords already computed in the last
source, so the change here is basically using that instead of emitting
the ir3_SHR to divide the byte-offset by 4.

The improvement in shader stats is dramatic, of up to ~15% in
instruction count in some cases. Tested on a5xx.

shader-db is unfortunately not very useful here because shaders that use
SSBO require GLSL versions that are not supported by freedreno yet.

For examples, most Khronos CTS tests under 'dEQP-GLES31.functional.ssbo.*'
are helped.

A random case:

dEQP-GLES31.functional.ssbo.layout.2_level_array.packed.row_major_mat3x2

with current master:

; CL prog 14/1: 1252 instructions, 0 half, 48 full
; 8 const, 8 constlen
; 61 (ss), 43 (sy)

with the SSBO dword-offset moved to NIR:

; CL prog 14/1: 1053 instructions, 0 half, 45 full
; 7 const, 7 constlen
; 34 (ss), 73 (sy)

The SHR previously emitted for every single SSBO instruction disappears
in most cases, and the dword-offset ends up embedded in the STGB
instruction as immediate in many cases as well.

No regressions observed with relevant CTS and piglit tests.
---
 src/freedreno/ir3/ir3_compiler_nir.c | 71 +++++++++++++++++++---------
 1 file changed, 48 insertions(+), 23 deletions(-)

diff --git a/src/freedreno/ir3/ir3_compiler_nir.c b/src/freedreno/ir3/ir3_compiler_nir.c
index 0e141f03181..c494913f254 100644
--- a/src/freedreno/ir3/ir3_compiler_nir.c
+++ b/src/freedreno/ir3/ir3_compiler_nir.c
@@ -760,7 +760,12 @@ emit_intrinsic_load_ssbo(struct ir3_context *ctx, nir_intrinsic_instr *intr,
 		offset,
 		create_immed(b, 0),
 	}, 2);
-	src1 = ir3_SHR_B(b, offset, 0, create_immed(b, 2), 0);
+
+	/* intrinsic->src[2] holds the dword-offset as placed by
+	 * 'ir3_nir_lower_io_offsets' pass.
+	 */
+	assert(intr->intrinsic == nir_intrinsic_load_ssbo_ir3);
+	src1 = ir3_get_src(ctx, &intr->src[2])[0];
 
 	ldgb = ir3_LDGB(b, create_immed(b, const_offset->u32[0]), 0,
 			src0, 0, src1, 0);
@@ -798,7 +803,13 @@ emit_intrinsic_store_ssbo(struct ir3_context *ctx, nir_intrinsic_instr *intr)
 	 * nir already *= 4:
 	 */
 	src0 = ir3_create_collect(ctx, ir3_get_src(ctx, &intr->src[0]), ncomp);
-	src1 = ir3_SHR_B(b, offset, 0, create_immed(b, 2), 0);
+
+	/* intrinsic->src[3] holds the dword-offset as placed by
+	 * 'ir3_nir_lower_io_offsets' pass.
+	 */
+	assert(intr->intrinsic == nir_intrinsic_store_ssbo_ir3);
+	src1 = ir3_get_src(ctx, &intr->src[3])[0];
+
 	src2 = ir3_create_collect(ctx, (struct ir3_instruction*[]){
 		offset,
 		create_immed(b, 0),
@@ -869,40 +880,50 @@ emit_intrinsic_atomic_ssbo(struct ir3_context *ctx, nir_intrinsic_instr *intr)
 	 * Note that nir already multiplies the offset by four
 	 */
 	src0 = ir3_get_src(ctx, &intr->src[2])[0];
-	src1 = ir3_SHR_B(b, offset, 0, create_immed(b, 2), 0);
+
+	/* intrinsic->src[3] holds the dword-offset as placed by
+	 * 'ir3_nir_lower_io_offsets' pass. It doesn't handle
+	 * 'atomic_comp_swap', though, because that intrinsic already used
+	 * all its 4 sources.
+	 */
+	if (intr->intrinsic == nir_intrinsic_ssbo_atomic_comp_swap)
+		src1 = ir3_SHR_B(b, offset, 0, create_immed(b, 2), 0);
+	else
+		src1 = ir3_get_src(ctx, &intr->src[3])[0];
+
 	src2 = ir3_create_collect(ctx, (struct ir3_instruction*[]){
 		offset,
 		create_immed(b, 0),
 	}, 2);
 
 	switch (intr->intrinsic) {
-	case nir_intrinsic_ssbo_atomic_add:
+	case nir_intrinsic_ssbo_atomic_add_ir3:
 		atomic = ir3_ATOMIC_ADD_G(b, ssbo, 0, src0, 0, src1, 0, src2, 0);
 		break;
-	case nir_intrinsic_ssbo_atomic_imin:
+	case nir_intrinsic_ssbo_atomic_imin_ir3:
 		atomic = ir3_ATOMIC_MIN_G(b, ssbo, 0, src0, 0, src1, 0, src2, 0);
 		type = TYPE_S32;
 		break;
-	case nir_intrinsic_ssbo_atomic_umin:
+	case nir_intrinsic_ssbo_atomic_umin_ir3:
 		atomic = ir3_ATOMIC_MIN_G(b, ssbo, 0, src0, 0, src1, 0, src2, 0);
 		break;
-	case nir_intrinsic_ssbo_atomic_imax:
+	case nir_intrinsic_ssbo_atomic_imax_ir3:
 		atomic = ir3_ATOMIC_MAX_G(b, ssbo, 0, src0, 0, src1, 0, src2, 0);
 		type = TYPE_S32;
 		break;
-	case nir_intrinsic_ssbo_atomic_umax:
+	case nir_intrinsic_ssbo_atomic_umax_ir3:
 		atomic = ir3_ATOMIC_MAX_G(b, ssbo, 0, src0, 0, src1, 0, src2, 0);
 		break;
-	case nir_intrinsic_ssbo_atomic_and:
+	case nir_intrinsic_ssbo_atomic_and_ir3:
 		atomic = ir3_ATOMIC_AND_G(b, ssbo, 0, src0, 0, src1, 0, src2, 0);
 		break;
-	case nir_intrinsic_ssbo_atomic_or:
+	case nir_intrinsic_ssbo_atomic_or_ir3:
 		atomic = ir3_ATOMIC_OR_G(b, ssbo, 0, src0, 0, src1, 0, src2, 0);
 		break;
-	case nir_intrinsic_ssbo_atomic_xor:
+	case nir_intrinsic_ssbo_atomic_xor_ir3:
 		atomic = ir3_ATOMIC_XOR_G(b, ssbo, 0, src0, 0, src1, 0, src2, 0);
 		break;
-	case nir_intrinsic_ssbo_atomic_exchange:
+	case nir_intrinsic_ssbo_atomic_exchange_ir3:
 		atomic = ir3_ATOMIC_XCHG_G(b, ssbo, 0, src0, 0, src1, 0, src2, 0);
 		break;
 	case nir_intrinsic_ssbo_atomic_comp_swap:
@@ -1639,24 +1660,28 @@ emit_intrinsic(struct ir3_context *ctx, nir_intrinsic_instr *intr)
 			}
 		}
 		break;
-	case nir_intrinsic_load_ssbo:
+		/* All SSBO intrinsics (except atomic_comp_swap) should have been
+		 * lowered by 'lower_io_offsets' pass and replaced by an ir3-specifc
+		 * version that adds the dword-offset in the last component.
+		 */
+	case nir_intrinsic_load_ssbo_ir3:
 		emit_intrinsic_load_ssbo(ctx, intr, dst);
 		break;
-	case nir_intrinsic_store_ssbo:
+	case nir_intrinsic_store_ssbo_ir3:
 		emit_intrinsic_store_ssbo(ctx, intr);
 		break;
 	case nir_intrinsic_get_buffer_size:
 		emit_intrinsic_ssbo_size(ctx, intr, dst);
 		break;
-	case nir_intrinsic_ssbo_atomic_add:
-	case nir_intrinsic_ssbo_atomic_imin:
-	case nir_intrinsic_ssbo_atomic_umin:
-	case nir_intrinsic_ssbo_atomic_imax:
-	case nir_intrinsic_ssbo_atomic_umax:
-	case nir_intrinsic_ssbo_atomic_and:
-	case nir_intrinsic_ssbo_atomic_or:
-	case nir_intrinsic_ssbo_atomic_xor:
-	case nir_intrinsic_ssbo_atomic_exchange:
+	case nir_intrinsic_ssbo_atomic_add_ir3:
+	case nir_intrinsic_ssbo_atomic_imin_ir3:
+	case nir_intrinsic_ssbo_atomic_umin_ir3:
+	case nir_intrinsic_ssbo_atomic_imax_ir3:
+	case nir_intrinsic_ssbo_atomic_umax_ir3:
+	case nir_intrinsic_ssbo_atomic_and_ir3:
+	case nir_intrinsic_ssbo_atomic_or_ir3:
+	case nir_intrinsic_ssbo_atomic_xor_ir3:
+	case nir_intrinsic_ssbo_atomic_exchange_ir3:
 	case nir_intrinsic_ssbo_atomic_comp_swap:
 		dst[0] = emit_intrinsic_atomic_ssbo(ctx, intr);
 		break;
-- 
2.20.1



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