[Mesa-dev] [PATCH] radv: enable denorms for 64-bit and 16-bit floats

[Samuel Pitoiset]

Similar to RadeonSI.

This fixes:
dEQP-VK.image.texel_view_compatible.graphic.basic.attachment_read.bc*r16g16b16a16_sfloat
dEQP-VK.image.extended_usage_bit.attachment_write.r16_sfloat

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
---
 src/amd/common/ac_nir_to_llvm.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/amd/common/ac_nir_to_llvm.c b/src/amd/common/ac_nir_to_llvm.c
index d9f2cb408c..9d9a1f911b 100644
--- a/src/amd/common/ac_nir_to_llvm.c
+++ b/src/amd/common/ac_nir_to_llvm.c
@@ -6879,6 +6879,20 @@ static void ac_compile_llvm_module(LLVMTargetMachineRef tm,
 	/* +3 for scratch wave offset and VCC */
 	config->num_sgprs = MAX2(config->num_sgprs,
 	                         shader_info->num_input_sgprs + 3);
+
+	/* Enable 64-bit and 16-bit denormals, because there is no performance
+	 * cost.
+	 *
+	 * If denormals are enabled, all floating-point output modifiers are
+	 * ignored.
+	 *
+	 * Don't enable denormals for 32-bit floats, because:
+	 * - Floating-point output modifiers would be ignored by the hw.
+	 * - Some opcodes don't support denormals, such as v_mad_f32. We would
+	 *   have to stop using those.
+	 * - SI & CI would be very slow.
+	 */
+	config->float_mode |= V_00B028_FP_64_DENORMS;
 }
 
 static void
-- 
2.15.1