cmd/gc: reject complex calls with mismatched argument types.

The specification says "the two arguments must be of the same
floating-point type."

R=rsc, gri
CC=golang-dev
https://golang.org/cl/7671045

src/cmd/gc/typecheck.c

@@ -1182,9 +1182,9 @@ typecheck1(Node **np, int top)
  defaultlit2(&l, &r, 0);
  n->left = l;
  n->right = r;
- if(l->type->etype != r->type->etype) {
+ if(!eqtype(l->type, r->type)) {
  badcmplx:
- yyerror("invalid operation: %N (complex of types %T, %T)", n, l->type, r->type);
+ yyerror("invalid operation: %N (mismatched types %T and %T)", n, l->type, r->type);
  goto error;
  }
  switch(l->type->etype) {

test/cmplx.go

@@ -9,12 +9,23 @@
 
 package main
 
+type (
+ Float32 float32
+ Float64 float64
+ Complex64 complex64
+ Complex128 complex128
+)
+
 var (
  f32 float32
  f64 float64
+ F32 Float32
+ F64 Float64
 
  c64 complex64
  c128 complex128
+ C64 Complex64
+ C128 Complex128
 )
 
 func main() {
@@ -25,4 +36,19 @@ func main() {
  _ = complex128(0) // ok
  _ = complex(f32, f64) // ERROR "complex"
  _ = complex(f64, f32) // ERROR "complex"
+ _ = complex(f32, F32) // ERROR "complex"
+ _ = complex(F32, f32) // ERROR "complex"
+ _ = complex(f64, F64) // ERROR "complex"
+ _ = complex(F64, f64) // ERROR "complex"
+
+ c128 = complex(f32, f32) // ERROR "cannot use"
+ c64 = complex(f64, f64) // ERROR "cannot use"
+
+ c64 = complex(1.0, 2.0) // ok, constant is untyped
+ c128 = complex(1.0, 2.0)
+ C64 = complex(1.0, 2.0)
+ C128 = complex(1.0, 2.0)
+
+ C64 = complex(f32, f32) // ERROR "cannot use"
+ C128 = complex(f64, f64) // ERROR "cannot use"
 }