location assignment: fix overlapping locations

Author: Firestar99

crates/rustc_codegen_spirv/src/codegen_cx/entry.rs

@@ -881,7 +881,7 @@ impl<'tcx> CodegenCx<'tcx> {
                 Decoration::Location,
                 std::iter::once(Operand::LiteralBit32(*location)),
             );
-            *location += 1;
+            *location += value_layout.size.bytes().div_ceil(16) as u32;
         }
 
         match storage_class {

tests/compiletests/ui/spirv-attr/location_assignment.stderr

@@ -19,9 +19,9 @@ OpName %5 "out4"
 OpMemberDecorate %9 0 Offset 0
 OpMemberDecorate %9 1 Offset 16
 OpDecorate %2 Location 0
-OpDecorate %3 Location 1
-OpDecorate %4 Location 2
-OpDecorate %5 Location 3
+OpDecorate %3 Location 2
+OpDecorate %4 Location 3
+OpDecorate %5 Location 7
 %10 = OpTypeFloat 32
 %11 = OpTypeVector %10 4
 %12 = OpTypeVector %10 2
@@ -68,11 +68,3 @@ OpStore %5 %19
 OpNoLine
 OpReturn
 OpFunctionEnd
-error: error:0:0 - [VUID-StandaloneSpirv-OpEntryPoint-08722] Entry-point has conflicting output location assignment at location 1, component 0
-         OpEntryPoint Vertex %1 "main" %out1 %out2 %out3 %out4
-   |
-   = note: spirv-val failed
-   = note: module `$TEST_BUILD_DIR/spirv-attr/location_assignment.vulkan1.2`
-
-error: aborting due to 1 previous error
-