[Mesa-dev] [RFC PATCH 1/4] radv: gather more info about push constants

[Samuel Pitoiset]

This is needed in order to inline some push constants when possible.
This also adds a new helper for initializing the pass.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
---
 src/amd/vulkan/radv_nir_to_llvm.c |  2 ++
 src/amd/vulkan/radv_private.h     |  2 ++
 src/amd/vulkan/radv_shader.h      |  4 ++++
 src/amd/vulkan/radv_shader_info.c | 32 ++++++++++++++++++++++++++++++-
 4 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/src/amd/vulkan/radv_nir_to_llvm.c b/src/amd/vulkan/radv_nir_to_llvm.c
index 5048d9d2493..b655e2c2e2c 100644
--- a/src/amd/vulkan/radv_nir_to_llvm.c
+++ b/src/amd/vulkan/radv_nir_to_llvm.c
@@ -3439,6 +3439,8 @@ LLVMModuleRef ac_translate_nir_to_llvm(struct ac_llvm_compiler *ac_llvm,
 
 	memset(shader_info, 0, sizeof(*shader_info));
 
+	radv_nir_shader_info_init(&shader_info->info);
+
 	for(int i = 0; i < shader_count; ++i)
 		radv_nir_shader_info_pass(shaders[i], options, &shader_info->info);
 
diff --git a/src/amd/vulkan/radv_private.h b/src/amd/vulkan/radv_private.h
index 85c18906f84..4c76521a045 100644
--- a/src/amd/vulkan/radv_private.h
+++ b/src/amd/vulkan/radv_private.h
@@ -1941,6 +1941,8 @@ void radv_nir_shader_info_pass(const struct nir_shader *nir,
 			       const struct radv_nir_compiler_options *options,
 			       struct radv_shader_info *info);
 
+void radv_nir_shader_info_init(struct radv_shader_info *info);
+
 struct radeon_winsys_sem;
 
 #define RADV_DEFINE_HANDLE_CASTS(__radv_type, __VkType)		\
diff --git a/src/amd/vulkan/radv_shader.h b/src/amd/vulkan/radv_shader.h
index 3652a811e80..0f049f9a528 100644
--- a/src/amd/vulkan/radv_shader.h
+++ b/src/amd/vulkan/radv_shader.h
@@ -162,6 +162,10 @@ struct radv_streamout_info {
 
 struct radv_shader_info {
 	bool loads_push_constants;
+	uint8_t min_push_constant_used;
+	uint8_t max_push_constant_used;
+	bool has_32bit_push_constants;
+	bool has_indirect_push_constants;
 	uint32_t desc_set_used_mask;
 	bool needs_multiview_view_index;
 	bool uses_invocation_id;
diff --git a/src/amd/vulkan/radv_shader_info.c b/src/amd/vulkan/radv_shader_info.c
index 7e5a3789af2..c9cd5fddc53 100644
--- a/src/amd/vulkan/radv_shader_info.c
+++ b/src/amd/vulkan/radv_shader_info.c
@@ -190,6 +190,30 @@ gather_intrinsic_store_deref_info(const nir_shader *nir,
 	}
 }
 
+static void
+gather_push_constant_info(const nir_shader *nir,
+			  const nir_intrinsic_instr *instr,
+			  struct radv_shader_info *info)
+{
+	nir_const_value *cval = nir_src_as_const_value(instr->src[0]);
+
+	if (!cval)
+		info->has_indirect_push_constants = true;
+
+	if (instr->dest.ssa.bit_size == 32)
+		info->has_32bit_push_constants = true;
+
+ 	int base = nir_intrinsic_base(instr);
+	int range = nir_intrinsic_range(instr);
+
+	if (base + range > info->max_push_constant_used)
+		info->max_push_constant_used = base + range;
+	if (base < info->min_push_constant_used)
+		info->min_push_constant_used = base;
+
+ 	info->loads_push_constants = true;
+}
+
 static void
 gather_intrinsic_info(const nir_shader *nir, const nir_intrinsic_instr *instr,
 		      struct radv_shader_info *info)
@@ -243,7 +267,7 @@ gather_intrinsic_info(const nir_shader *nir, const nir_intrinsic_instr *instr,
 		info->uses_prim_id = true;
 		break;
 	case nir_intrinsic_load_push_constant:
-		info->loads_push_constants = true;
+		gather_push_constant_info(nir, instr, info);
 		break;
 	case nir_intrinsic_vulkan_resource_index:
 		info->desc_set_used_mask |= (1 << nir_intrinsic_desc_set(instr));
@@ -504,6 +528,12 @@ gather_xfb_info(const nir_shader *nir, struct radv_shader_info *info)
 	ralloc_free(xfb);
 }
 
+void
+radv_nir_shader_info_init(struct radv_shader_info *info)
+{
+	info->min_push_constant_used = -1;
+}
+
 void
 radv_nir_shader_info_pass(const struct nir_shader *nir,
 			  const struct radv_nir_compiler_options *options,
-- 
2.20.1