nir: Support printing cmat constants

A cooperative matrix can only be constructed from a single
scalar value. Print that value, wrapped by a function call that
looks like a type-constructor.

This adds a test case that will otherwise assert out in spirv2nir.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35757>

src/compiler/nir/nir_print.c

@@ -714,6 +714,15 @@ print_constant(nir_constant *c, const struct glsl_type *type, print_state *state
       }
       break;
 
+   case GLSL_TYPE_COOPERATIVE_MATRIX:
+      // This occurs as the constant initializer for a cmat variable.
+      // In this case it's a scalar constant, and its word value is
+      // c->values[0], but we have to interpet it via the component type.
+      fprintf(fp, "%s(", glsl_get_type_name(type));
+      print_constant(c, glsl_get_cmat_element(type), state);
+      fprintf(fp, ")");
+      break;
+
    default:
       unreachable("not reached");
    }

src/compiler/spirv/meson.build

@@ -103,6 +103,7 @@ if with_tests
         'tests/helpers.h',
         'tests/avail_vis.cpp',
         'tests/volatile.cpp',
+        'tests/cmat.cpp',
         'tests/control_flow_tests.cpp',
         'tests/non_semantic.cpp',
         'tests/workarounds.cpp',

src/compiler/spirv/tests/cmat.cpp

@@ -0,0 +1,141 @@
+/*
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <gtest/gtest.h>
+
+#include "util/memstream.h"
+
+#include "helpers.h"
+
+struct CooperativeMatrix : public spirv_test {
+   void SetUp() {
+     spirv_caps.CooperativeMatrixKHR = true;
+     shader_text = NULL;
+   }
+
+   void TearDown() {
+     free(shader_text);
+   }
+
+   // Prints the shader to a newly allocated null-terminated string, and
+   // saves it into 'shader_text'. Returns NULL if resources were exhausted.
+   char *to_string(nir_shader *shader) {
+      free(shader_text);
+      shader_text = NULL;
+      size_t result_size = 0;
+      struct u_memstream mem;
+      if (u_memstream_open(&mem, &shader_text, &result_size)) {
+         FILE * memf = u_memstream_get(&mem);
+         nir_print_shader(shader, memf);
+         u_memstream_close(&mem);
+      }
+      return shader_text;
+   }
+
+   char * shader_text;
+};
+
+
+TEST_F(CooperativeMatrix, VariableInitializer)
+{
+   // This module creates a cooperative matrix variable in Function storage
+   // class with an initializer. spirv2nir should be able to print it,
+   // including the initializer value.
+
+   /*
+   ; SPIR-V
+   ; Version: 1.3
+   ; Generator: Khronos SPIR-V Tools Assembler; 0
+   ; Bound: 26
+   ; Schema: 0
+                  OpCapability Shader
+                  OpCapability VulkanMemoryModel
+                  OpCapability VulkanMemoryModelDeviceScope
+                  OpCapability CooperativeMatrixKHR
+                  OpExtension "SPV_KHR_vulkan_memory_model"
+                  OpExtension "SPV_KHR_cooperative_matrix"
+                  OpMemoryModel Logical Vulkan
+                  OpEntryPoint GLCompute %main "main"
+                  OpExecutionMode %main LocalSize 64 1 1
+                  OpMemberName %buf_block_tint_explicit_layout 0 "inner"
+                  OpName %buf_block_tint_explicit_layout "buf_block_tint_explicit_layout"
+                  OpName %main "main"
+                  OpName %m "m"
+                  OpDecorate %_arr_float_uint_64 ArrayStride 4
+                  OpMemberDecorate %buf_block_tint_explicit_layout 0 Offset 0
+                  OpDecorate %buf_block_tint_explicit_layout Block
+                  OpDecorate %5 DescriptorSet 0
+                  OpDecorate %5 Binding 0
+         %float = OpTypeFloat 32
+          %uint = OpTypeInt 32 0
+       %uint_64 = OpConstant %uint 64
+   %_arr_float_uint_64 = OpTypeArray %float %uint_64
+   %buf_block_tint_explicit_layout = OpTypeStruct %_arr_float_uint_64
+   %_ptr_StorageBuffer_buf_block_tint_explicit_layout = OpTypePointer StorageBuffer %buf_block_tint_explicit_layout
+             %5 = OpVariable %_ptr_StorageBuffer_buf_block_tint_explicit_layout StorageBuffer
+          %void = OpTypeVoid
+            %11 = OpTypeFunction %void
+        %uint_3 = OpConstant %uint 3
+        %uint_8 = OpConstant %uint 8
+        %uint_2 = OpConstant %uint 2
+            %15 = OpTypeCooperativeMatrixKHR %float %uint_3 %uint_8 %uint_8 %uint_2
+   %_ptr_Function_15 = OpTypePointer Function %15
+     %float_1_5 = OpConstant %float 1.5
+            %18 = OpConstantComposite %15 %float_1_5
+   %_ptr_StorageBuffer__arr_float_uint_64 = OpTypePointer StorageBuffer %_arr_float_uint_64
+        %uint_0 = OpConstant %uint 0
+   %_ptr_StorageBuffer_float = OpTypePointer StorageBuffer %float
+          %main = OpFunction %void None %11
+            %22 = OpLabel
+             %m = OpVariable %_ptr_Function_15 Function %18
+            %23 = OpLoad %15 %m None
+            %24 = OpAccessChain %_ptr_StorageBuffer__arr_float_uint_64 %5 %uint_0
+            %25 = OpAccessChain %_ptr_StorageBuffer_float %24 %uint_0
+                  OpCooperativeMatrixStoreKHR %25 %23 %uint_0 %uint_8 NonPrivatePointer
+                  OpReturn
+                  OpFunctionEnd
+    */
+   static const uint32_t words[] = {
+      0x07230203, 0x00010300, 0x00070000, 0x0000001a, 0x00000000, 0x00020011,
+      0x00000001, 0x00020011, 0x000014e1, 0x00020011, 0x000014e2, 0x00020011,
+      0x00001786, 0x0008000a, 0x5f565053, 0x5f52484b, 0x6b6c7576, 0x6d5f6e61,
+      0x726f6d65, 0x6f6d5f79, 0x006c6564, 0x0008000a, 0x5f565053, 0x5f52484b,
+      0x706f6f63, 0x74617265, 0x5f657669, 0x7274616d, 0x00007869, 0x0003000e,
+      0x00000000, 0x00000003, 0x0005000f, 0x00000005, 0x00000001, 0x6e69616d,
+      0x00000000, 0x00060010, 0x00000001, 0x00000011, 0x00000040, 0x00000001,
+      0x00000001, 0x00050006, 0x00000002, 0x00000000, 0x656e6e69, 0x00000072,
+      0x000a0005, 0x00000002, 0x5f667562, 0x636f6c62, 0x69745f6b, 0x655f746e,
+      0x696c7078, 0x5f746963, 0x6f79616c, 0x00007475, 0x00040005, 0x00000001,
+      0x6e69616d, 0x00000000, 0x00030005, 0x00000003, 0x0000006d, 0x00040047,
+      0x00000004, 0x00000006, 0x00000004, 0x00050048, 0x00000002, 0x00000000,
+      0x00000023, 0x00000000, 0x00030047, 0x00000002, 0x00000002, 0x00040047,
+      0x00000005, 0x00000022, 0x00000000, 0x00040047, 0x00000005, 0x00000021,
+      0x00000000, 0x00030016, 0x00000006, 0x00000020, 0x00040015, 0x00000007,
+      0x00000020, 0x00000000, 0x0004002b, 0x00000007, 0x00000008, 0x00000040,
+      0x0004001c, 0x00000004, 0x00000006, 0x00000008, 0x0003001e, 0x00000002,
+      0x00000004, 0x00040020, 0x00000009, 0x0000000c, 0x00000002, 0x0004003b,
+      0x00000009, 0x00000005, 0x0000000c, 0x00020013, 0x0000000a, 0x00030021,
+      0x0000000b, 0x0000000a, 0x0004002b, 0x00000007, 0x0000000c, 0x00000003,
+      0x0004002b, 0x00000007, 0x0000000d, 0x00000008, 0x0004002b, 0x00000007,
+      0x0000000e, 0x00000002, 0x00071168, 0x0000000f, 0x00000006, 0x0000000c,
+      0x0000000d, 0x0000000d, 0x0000000e, 0x00040020, 0x00000010, 0x00000007,
+      0x0000000f, 0x0004002b, 0x00000006, 0x00000011, 0x3fc00000, 0x0004002c,
+      0x0000000f, 0x00000012, 0x00000011, 0x00040020, 0x00000013, 0x0000000c,
+      0x00000004, 0x0004002b, 0x00000007, 0x00000014, 0x00000000, 0x00040020,
+      0x00000015, 0x0000000c, 0x00000006, 0x00050036, 0x0000000a, 0x00000001,
+      0x00000000, 0x0000000b, 0x000200f8, 0x00000016, 0x0005003b, 0x00000010,
+      0x00000003, 0x00000007, 0x00000012, 0x0005003d, 0x0000000f, 0x00000017,
+      0x00000003, 0x00000000, 0x00050041, 0x00000013, 0x00000018, 0x00000005,
+      0x00000014, 0x00050041, 0x00000015, 0x00000019, 0x00000018, 0x00000014,
+      0x0006116a, 0x00000019, 0x00000017, 0x00000014, 0x0000000d, 0x00000020,
+      0x000100fd, 0x00010038,
+   };
+   get_nir(sizeof(words) / sizeof(words[0]), words);
+   ASSERT_TRUE(shader);
+
+   char *text = to_string(shader);
+   const char* expected = "m = { coopmat<float, SCOPE_SUBGROUP, 8, 8, ACCUMULATOR>(1.500000) }";
+   EXPECT_NE(nullptr, strstr(text, expected)) << text;
+}