[Mesa-dev] [PATCH 14/19] radeonsi: implement TGSI_SEMANTIC_SUBGROUP_*

[Nicolai Hähnle]

From: Nicolai Hähnle <nicolai.haehnle at amd.com>

64-bit system values are stored as v2i32 to simplify the fetch logic.
---
 src/gallium/drivers/radeonsi/si_shader.c | 40 ++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c
index 4682a8e..12eca9f 100644
--- a/src/gallium/drivers/radeonsi/si_shader.c
+++ b/src/gallium/drivers/radeonsi/si_shader.c
@@ -1596,20 +1596,60 @@ static void declare_system_value(
 						   ctx->i1, NULL, 0,
 						   LP_FUNC_ATTR_READNONE);
 			value = LLVMBuildNot(gallivm->builder, value, "");
 			value = LLVMBuildSExt(gallivm->builder, value, ctx->i32, "");
 		} else {
 			assert(!"TGSI_SEMANTIC_HELPER_INVOCATION unsupported");
 			return;
 		}
 		break;
 
+	case TGSI_SEMANTIC_SUBGROUP_SIZE:
+		value = LLVMConstInt(ctx->i32, 64, 0);
+		break;
+
+	case TGSI_SEMANTIC_SUBGROUP_INVOCATION:
+		value = ac_get_thread_id(&ctx->ac);
+		break;
+
+	case TGSI_SEMANTIC_SUBGROUP_EQ_MASK:
+	{
+		LLVMValueRef id = ac_get_thread_id(&ctx->ac);
+		id = LLVMBuildZExt(gallivm->builder, id, ctx->i64, "");
+		value = LLVMBuildShl(gallivm->builder, LLVMConstInt(ctx->i64, 1, 0), id, "");
+		value = LLVMBuildBitCast(gallivm->builder, value, ctx->v2i32, "");
+		break;
+	}
+
+	case TGSI_SEMANTIC_SUBGROUP_GE_MASK:
+	case TGSI_SEMANTIC_SUBGROUP_GT_MASK:
+	case TGSI_SEMANTIC_SUBGROUP_LE_MASK:
+	case TGSI_SEMANTIC_SUBGROUP_LT_MASK:
+	{
+		LLVMValueRef id = ac_get_thread_id(&ctx->ac);
+		if (decl->Semantic.Name == TGSI_SEMANTIC_SUBGROUP_GT_MASK ||
+		    decl->Semantic.Name == TGSI_SEMANTIC_SUBGROUP_LE_MASK) {
+			/* All bits set except LSB */
+			value = LLVMConstInt(ctx->i64, -2, 0);
+		} else {
+			/* All bits set */
+			value = LLVMConstInt(ctx->i64, -1, 0);
+		}
+		id = LLVMBuildZExt(gallivm->builder, id, ctx->i64, "");
+		value = LLVMBuildShl(gallivm->builder, value, id, "");
+		if (decl->Semantic.Name == TGSI_SEMANTIC_SUBGROUP_LE_MASK ||
+		    decl->Semantic.Name == TGSI_SEMANTIC_SUBGROUP_LT_MASK)
+			value = LLVMBuildNot(gallivm->builder, value, "");
+		value = LLVMBuildBitCast(gallivm->builder, value, ctx->v2i32, "");
+		break;
+	}
+
 	default:
 		assert(!"unknown system value");
 		return;
 	}
 
 	radeon_bld->system_values[index] = value;
 }
 
 static void declare_compute_memory(struct si_shader_context *radeon_bld,
                                    const struct tgsi_full_declaration *decl)
-- 
2.9.3