Add check for DOUBLE in low versions (#2223)

Test/330.frag

@@ -149,3 +149,7 @@ layout(location=6) uniform ColorsBuffer // ERROR: location cannot be applied in
 } colorsBuffer;
 
 
+void testOverload() {
+    float overloadTest = 42;
+    overloadTest = smoothstep(0, 1, overloadTest);
+}
\ No newline at end of file

Test/baseResults/330.frag.out

@@ -83,6 +83,22 @@ ERROR: node is still EOpNull!
 0:135        'KeyMem' ( global structure{ global int precise})
 0:135        Constant:
 0:135          0 (const int)
+0:152  Function Definition: testOverload( ( global void)
+0:152    Function Parameters: 
+0:153    Sequence
+0:153      Sequence
+0:153        move second child to first child ( temp float)
+0:153          'overloadTest' ( temp float)
+0:153          Constant:
+0:153            42.000000
+0:154      move second child to first child ( temp float)
+0:154        'overloadTest' ( temp float)
+0:154        smoothstep ( global float)
+0:154          Constant:
+0:154            0.000000
+0:154          Constant:
+0:154            1.000000
+0:154          'overloadTest' ( temp float)
 0:?   Linker Objects
 0:?     'inVar' ( smooth in 4-component vector of float)
 0:?     'outVar' (layout( location=0 index=0) out 4-component vector of float)

glslang/MachineIndependent/Intermediate.cpp

@@ -1733,12 +1733,14 @@ bool TIntermediate::canImplicitlyPromote(TBasicType from, TBasicType to, TOperat
             case EbtUint64:
             case EbtFloat:
             case EbtDouble:
-                return true;
+                return version >= 400 || extensionRequested(E_GL_ARB_gpu_shader_fp64);
             case EbtInt16:
             case EbtUint16:
-                return extensionRequested(E_GL_AMD_gpu_shader_int16);
+                return (version >= 400 || extensionRequested(E_GL_ARB_gpu_shader_fp64)) &&
+                       extensionRequested(E_GL_AMD_gpu_shader_int16);
             case EbtFloat16:
-                return extensionRequested(E_GL_AMD_gpu_shader_half_float);
+                return (version >= 400 || extensionRequested(E_GL_ARB_gpu_shader_fp64)) &&
+                       extensionRequested(E_GL_AMD_gpu_shader_half_float);
             default:
                 return false;
            }