Prefer using spirv-as for assembly SPIR-V assembly if possible

* Since we no longer can link shaderc we have external dependencies anyway, most
  likely from the vulkan SDK. shaderc has never fixed the inability to apply
  target env to shader assembly so this means we can specifically target some
  SPIR-V versions.

util/test/demos/test_common.cpp

@@ -253,27 +253,38 @@ void LoadXPM(const char **XPM, Texture &tex)
 }
 
 static std::string externalCompiler;
+static std::string externalASMCompiler;
+
+bool CheckCompiler(std::string compiler)
+{
+  FILE *pipe = popen((compiler + EXECUTABLE_SUFFIX " --version 2>&1").c_str(), "r");
+
+  if(!pipe)
+    return false;
+
+  char dummy[512];
+  while(!feof(pipe))
+  {
+    fread(dummy, 1, 512, pipe);
+  }
+
+  int code = pclose(pipe);
+
+  return (WEXITSTATUS(code) == 0);
+}
 
 bool SpvCompilationSupported()
 {
+  if(CheckCompiler("spirv-as"))
+    externalASMCompiler = "spirv-as";
+
   for(std::string compiler : {"glslc", "glslangValidator"})
   {
-    FILE *pipe = popen((compiler + EXECUTABLE_SUFFIX " --version 2>&1").c_str(), "r");
-
-    if(!pipe)
-      continue;
-
-    char dummy[512];
-    while(!feof(pipe))
-    {
-      fread(dummy, 1, 512, pipe);
-    }
-
-    int code = pclose(pipe);
-
-    if(WEXITSTATUS(code) == 0)
+    if(CheckCompiler(compiler))
     {
       externalCompiler = compiler;
+      if(externalASMCompiler.empty())
+        externalASMCompiler = compiler;
       return true;
     }
   }
@@ -302,7 +313,25 @@ std::vector<uint32_t> CompileShaderToSpv(const char *demo_name, const std::strin
   std::string infile = path + "/input";
   std::string outfile = path + "/output";
 
-  if(externalCompiler == "glslc")
+  if(lang == ShaderLang::spvasm && externalASMCompiler == "spirv-as")
+  {
+    command_line = "spirv-as" EXECUTABLE_SUFFIX;
+
+    if(target == SPIRVTarget::opengl)
+      command_line += " --target-env=opengl";
+    else if(target == SPIRVTarget::vulkan)
+      command_line += " --target-env=vulkan1.0";
+    else if(target == SPIRVTarget::vulkan11)
+      command_line += " --target-env=vulkan1.1";
+    else if(target == SPIRVTarget::vulkan12)
+      command_line += " --target-env=vulkan1.2";
+
+    command_line += " -o ";
+    command_line += outfile;
+    command_line += " ";
+    command_line += infile;
+  }
+  else if(externalCompiler == "glslc")
   {
     command_line = "glslc" EXECUTABLE_SUFFIX;
     if(debug_info)

util/test/demos/vk/vk_multi_entry.cpp

@@ -35,10 +35,10 @@ RD_TEST(VK_Multi_Entry, VulkanGraphicsTest)
                OpMemoryModel Logical GLSL450
 
                OpEntryPoint Vertex %fakev "fake" %posout
-               OpEntryPoint Fragment %fakef "fake" %ColorF
+               OpEntryPoint Fragment %fakef "fake" %ColorF %push %tex1
 
                OpEntryPoint Vertex %mainv "main" %vertOut %Position %_ %Color %UV
-               OpEntryPoint Fragment %mainf "main" %ColorF %vertIn
+               OpEntryPoint Fragment %mainf "main" %ColorF %vertIn %push %tex
 
                OpExecutionMode %fakef OriginUpperLeft
                OpExecutionMode %mainf OriginUpperLeft
@@ -241,7 +241,7 @@ RD_TEST(VK_Multi_Entry, VulkanGraphicsTest)
     };
 
     VkPipelineShaderStageCreateInfo shad = CompileShaderModule(
-        combined_asm, ShaderLang::spvasm, ShaderStage::vert, "main", {}, SPIRVTarget::vulkan);
+        combined_asm, ShaderLang::spvasm, ShaderStage::vert, "main", {}, SPIRVTarget::vulkan12);
 
     pipeCreateInfo.stages = {
         shad,

util/test/demos/vk/vk_shader_debug_zoo.cpp

@@ -3339,7 +3339,7 @@ OpBranch %_bottomlabel
 %_addr_bda_data_struct = OpLoad %uint2 %_ptr_addr_bda_data_struct
 %_ptr_bda_data_struct = OpBitcast %ptr_PhysicalStorageBuffer_bda_data_struct_f32_4 %_addr_bda_data_struct
 %_ptr_f32 = OpPtrAccessChain %ptr_PhysicalStorageBuffer_f32 %_ptr_bda_data_struct %int_dyn_1
-%_out_float = OpLoad %float %_ptr_f32 Aligned 16
+%_out_float = OpLoad %float %_ptr_f32 Aligned 4
 )EOTEST",
           // OpPtrAccessChain : float[] : ArrayStride 8
           R"EOTEST(
@@ -3347,7 +3347,7 @@ OpBranch %_bottomlabel
 %_addr_bda_data_struct = OpLoad %uint2 %_ptr_addr_bda_data_struct
 %_ptr_bda_data_struct = OpBitcast %ptr_PhysicalStorageBuffer_bda_data_struct_f32_8 %_addr_bda_data_struct
 %_ptr_f32 = OpPtrAccessChain %ptr_PhysicalStorageBuffer_f32 %_ptr_bda_data_struct %int_dyn_1
-%_out_float = OpLoad %float %_ptr_f32 Aligned 16
+%_out_float = OpLoad %float %_ptr_f32 Aligned 4
 )EOTEST",
           // OpPtrAccessChain : float[] : ArrayStride 12
           R"EOTEST(
@@ -3355,7 +3355,7 @@ OpBranch %_bottomlabel
 %_addr_bda_data_struct = OpLoad %uint2 %_ptr_addr_bda_data_struct
 %_ptr_bda_data_struct = OpBitcast %ptr_PhysicalStorageBuffer_bda_data_struct_f32_12 %_addr_bda_data_struct
 %_ptr_f32 = OpPtrAccessChain %ptr_PhysicalStorageBuffer_f32 %_ptr_bda_data_struct %int_dyn_1
-%_out_float = OpLoad %float %_ptr_f32 Aligned 16
+%_out_float = OpLoad %float %_ptr_f32 Aligned 4
 )EOTEST",
           // Load through a bda ptr array which is a member of a structure pointed to by a uint2 address
           R"EOTEST(
@@ -5021,11 +5021,6 @@ OpMemberDecorate %cbuffer_struct 17 Offset 216    ; double doublePackSource
 
     SPIRVTarget target = SPIRVTarget::vulkan;
 
-    if(vk_version >= 0x11)
-      target = SPIRVTarget::vulkan11;
-    if(vk_version >= 0x12)
-      target = SPIRVTarget::vulkan12;
-
     pipeCreateInfo.stages = {
         CompileShaderModule(vertex, ShaderLang::glsl, ShaderStage::vert, "main"),
         CompileShaderModule(make_pixel_asm(), ShaderLang::spvasm, ShaderStage::frag, "main", {},