amd/common: add ac_get_spi_shader_z_format()

ac_shader_util.c will contain shader helpers for RadeonSI
and RADV.

Signed-off-by: Samuel Pitoiset <[email protected]>
Reviewed-by: Bas Nieuwenhuizen <[email protected]>

1 files changed, 45 insertions, 0 deletions

diff --git a/src/amd/common/ac_shader_util.c b/src/amd/common/ac_shader_util.c
new file mode 100644
index 00000000000..9d33a465591
--- /dev/null
+++ b/src/amd/common/ac_shader_util.c
@@ -0,0 +1,45 @@
+/*
+ * Copyright 2012 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "ac_shader_util.h"
+#include "sid.h"
+
+unsigned
+ac_get_spi_shader_z_format(bool writes_z, bool writes_stencil,
+			   bool writes_samplemask)
+{
+	if (writes_z) {
+		/* Z needs 32 bits. */
+		if (writes_samplemask)
+			return V_028710_SPI_SHADER_32_ABGR;
+		else if (writes_stencil)
+			return V_028710_SPI_SHADER_32_GR;
+		else
+			return V_028710_SPI_SHADER_32_R;
+	} else if (writes_stencil || writes_samplemask) {
+		/* Both stencil and sample mask need only 16 bits. */
+		return V_028710_SPI_SHADER_UINT16_ABGR;
+	} else {
+		return V_028710_SPI_SHADER_ZERO;
+	}
+}