Code that directly uses _Decimal* types on architectures not
supporting DFP is properly diagnosed ("error: decimal floating-point
not supported for this target"), via a call to
targetm.decimal_float_supported_p, if the _Decimal32, _Decimal64 or
_Decimal128 keywords are used to access it. Use via mode attributes
is also diagnosed ("unable to emulate 'SD'"); so is use of the
FLOAT_CONST_DECIMAL64 pragma. However, it is possible to access those
types via typeof applied to constants or built-in functions without
such an error. I expect that there are ways to get an ICE from this;
certainly it uses a completely undefined ABI.
This patch arranges for the types not to exist in the compiler at all
when DFP is not supported. As is done with unsupported _FloatN /
_FloatNx types, the global tree nodes are left as NULL_TREE, and the
built-in function machinery is made to use error_mark_node for them in
that case in builtin-types.def, so that the built-in functions are
unavailable. Code handling constants is adjusted to give an error,
and other code that might not work with the global tree nodes being
NULL_TREE is also updated.
Bootstrapped with no regressions for x86_64-pc-linux-gnu. Also tested
with no regressions for cross to aarch64-linux-gnu, as a configuration
without DFP support. OK to commit (the changes that aren't C front-end
changes)?
gcc:
2019-11-22 Joseph Myers <[email protected]>
PR c/91985
* builtin-types.def (BT_DFLOAT32, BT_DFLOAT64, BT_DFLOAT128)
(BT_DFLOAT32_PTR, BT_DFLOAT64_PTR, BT_DFLOAT128_PTR): Define to
error_mark_node if corresponding global tree node is NULL.
* tree.c (build_common_tree_nodes): Do not initialize
dfloat32_type_node, dfloat64_type_node or dfloat128_type_node if
decimal floating-point not supported.
gcc/c:
2019-11-22 Joseph Myers <[email protected]>
PR c/91985
* c-decl.c (finish_declspecs): Use int instead of decimal
floating-point types if decimal floating-point not supported.
gcc/c-family:
2019-11-22 Joseph Myers <[email protected]>
PR c/91985
* c-common.c (c_common_type_for_mode): Handle decimal
floating-point types being NULL_TREE.
* c-format.c (get_format_for_type_1): Handle specified types being
NULL_TREE.
* c-lex.c (interpret_float): Give an error for decimal
floating-point constants when decimal floating-point not
supported.
gcc/lto:
2019-11-22 Joseph Myers <[email protected]>
PR c/91985
* lto-lang.c (lto_type_for_mode): Handle decimal floating-point
types being NULL_TREE.
gcc/testsuite:
2019-11-22 Joseph Myers <[email protected]>
PR c/91985
* gcc.dg/c2x-no-dfp-1.c, gcc.dg/gnu2x-builtins-no-dfp-1.c: New
tests.
* gcc.dg/fltconst-pedantic-dfp.c: Expect errors when decimal
floating-point not supported.
Index: gcc/builtin-types.def
===================================================================
--- gcc/builtin-types.def (revision 278603)
+++ gcc/builtin-types.def (working copy)
@@ -136,12 +136,24 @@ DEF_PRIMITIVE_TYPE (BT_WINT, wint_type_node)
DEF_PRIMITIVE_TYPE (BT_STRING, string_type_node)
DEF_PRIMITIVE_TYPE (BT_CONST_STRING, const_string_type_node)
-DEF_PRIMITIVE_TYPE (BT_DFLOAT32, dfloat32_type_node)
-DEF_PRIMITIVE_TYPE (BT_DFLOAT64, dfloat64_type_node)
-DEF_PRIMITIVE_TYPE (BT_DFLOAT128, dfloat128_type_node)
-DEF_PRIMITIVE_TYPE (BT_DFLOAT32_PTR, dfloat32_ptr_type_node)
-DEF_PRIMITIVE_TYPE (BT_DFLOAT64_PTR, dfloat64_ptr_type_node)
-DEF_PRIMITIVE_TYPE (BT_DFLOAT128_PTR, dfloat128_ptr_type_node)
+DEF_PRIMITIVE_TYPE (BT_DFLOAT32, (dfloat32_type_node
+ ? dfloat32_type_node
+ : error_mark_node))
+DEF_PRIMITIVE_TYPE (BT_DFLOAT64, (dfloat64_type_node
+ ? dfloat64_type_node
+ : error_mark_node))
+DEF_PRIMITIVE_TYPE (BT_DFLOAT128, (dfloat128_type_node
+ ? dfloat128_type_node
+ : error_mark_node))
+DEF_PRIMITIVE_TYPE (BT_DFLOAT32_PTR, (dfloat32_ptr_type_node
+ ? dfloat32_ptr_type_node
+ : error_mark_node))
+DEF_PRIMITIVE_TYPE (BT_DFLOAT64_PTR, (dfloat64_ptr_type_node
+ ? dfloat64_ptr_type_node
+ : error_mark_node))
+DEF_PRIMITIVE_TYPE (BT_DFLOAT128_PTR, (dfloat128_ptr_type_node
+ ? dfloat128_ptr_type_node
+ : error_mark_node))
DEF_PRIMITIVE_TYPE (BT_VALIST_REF, va_list_ref_type_node)
DEF_PRIMITIVE_TYPE (BT_VALIST_ARG, va_list_arg_type_node)
Index: gcc/c/c-decl.c
===================================================================
--- gcc/c/c-decl.c (revision 278603)
+++ gcc/c/c-decl.c (working copy)
@@ -11619,7 +11619,9 @@ finish_declspecs (struct c_declspecs *specs)
case cts_dfloat128:
gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p
&& !specs->signed_p && !specs->unsigned_p &&
!specs->complex_p);
- if (specs->typespec_word == cts_dfloat32)
+ if (!targetm.decimal_float_supported_p ())
+ specs->type = integer_type_node;
+ else if (specs->typespec_word == cts_dfloat32)
specs->type = dfloat32_type_node;
else if (specs->typespec_word == cts_dfloat64)
specs->type = dfloat64_type_node;
Index: gcc/c-family/c-common.c
===================================================================
--- gcc/c-family/c-common.c (revision 278603)
+++ gcc/c-family/c-common.c (working copy)
@@ -2321,11 +2321,14 @@ c_common_type_for_mode (machine_mode mode, int uns
return build_vector_type_for_mode (inner_type, mode);
}
- if (mode == TYPE_MODE (dfloat32_type_node))
+ if (dfloat32_type_node != NULL_TREE
+ && mode == TYPE_MODE (dfloat32_type_node))
return dfloat32_type_node;
- if (mode == TYPE_MODE (dfloat64_type_node))
+ if (dfloat64_type_node != NULL_TREE
+ && mode == TYPE_MODE (dfloat64_type_node))
return dfloat64_type_node;
- if (mode == TYPE_MODE (dfloat128_type_node))
+ if (dfloat128_type_node != NULL_TREE
+ && mode == TYPE_MODE (dfloat128_type_node))
return dfloat128_type_node;
if (ALL_SCALAR_FIXED_POINT_MODE_P (mode))
Index: gcc/c-family/c-format.c
===================================================================
--- gcc/c-family/c-format.c (revision 278603)
+++ gcc/c-family/c-format.c (working copy)
@@ -4390,7 +4390,7 @@ get_format_for_type_1 (const format_kind_info *fki
for (int i = 0; i < FMT_LEN_MAX; i++)
{
const format_type_detail *ftd = &spec->types[i];
- if (!ftd->type)
+ if (!ftd->type || *ftd->type == NULL_TREE)
continue;
if (matching_type_p (*ftd->type, effective_arg_type))
{
Index: gcc/c-family/c-lex.c
===================================================================
--- gcc/c-family/c-lex.c (revision 278603)
+++ gcc/c-family/c-lex.c (working copy)
@@ -877,7 +877,12 @@ interpret_float (const cpp_token *token, unsigned
/* Decode type based on width and properties. */
if (flags & CPP_N_DFLOAT)
- if ((flags & CPP_N_WIDTH) == CPP_N_LARGE)
+ if (!targetm.decimal_float_supported_p ())
+ {
+ error ("decimal floating-point not supported for this target");
+ return error_mark_node;
+ }
+ else if ((flags & CPP_N_WIDTH) == CPP_N_LARGE)
type = dfloat128_type_node;
else if ((flags & CPP_N_WIDTH) == CPP_N_SMALL)
type = dfloat32_type_node;
Index: gcc/lto/lto-lang.c
===================================================================
--- gcc/lto/lto-lang.c (revision 278603)
+++ gcc/lto/lto-lang.c (working copy)
@@ -1051,11 +1051,14 @@ lto_type_for_mode (machine_mode mode, int unsigned
return build_vector_type_for_mode (inner_type, mode);
}
- if (mode == TYPE_MODE (dfloat32_type_node))
+ if (dfloat32_type_node != NULL_TREE
+ && mode == TYPE_MODE (dfloat32_type_node))
return dfloat32_type_node;
- if (mode == TYPE_MODE (dfloat64_type_node))
+ if (dfloat64_type_node != NULL_TREE
+ && mode == TYPE_MODE (dfloat64_type_node))
return dfloat64_type_node;
- if (mode == TYPE_MODE (dfloat128_type_node))
+ if (dfloat128_type_node != NULL_TREE
+ && mode == TYPE_MODE (dfloat128_type_node))
return dfloat128_type_node;
if (ALL_SCALAR_FIXED_POINT_MODE_P (mode))
Index: gcc/testsuite/gcc.dg/c2x-no-dfp-1.c
===================================================================
--- gcc/testsuite/gcc.dg/c2x-no-dfp-1.c (nonexistent)
+++ gcc/testsuite/gcc.dg/c2x-no-dfp-1.c (working copy)
@@ -0,0 +1,12 @@
+/* Test DFP types and constants rejected if no DFP support. Bug
+ 91985. */
+/* { dg-do compile { target { ! dfp } } } */
+/* { dg-options "-std=c2x" } */
+
+_Decimal32 d32a; /* { dg-error "not supported" } */
+_Decimal64 d64a; /* { dg-error "not supported" } */
+_Decimal128 d128a; /* { dg-error "not supported" } */
+
+_Bool d32b = 1.0DF; /* { dg-error "not supported" } */
+_Bool d64b = 1.0DD; /* { dg-error "not supported" } */
+_Bool d128b = 1.0DL; /* { dg-error "not supported" } */
Index: gcc/testsuite/gcc.dg/fltconst-pedantic-dfp.c
===================================================================
--- gcc/testsuite/gcc.dg/fltconst-pedantic-dfp.c (revision 278603)
+++ gcc/testsuite/gcc.dg/fltconst-pedantic-dfp.c (working copy)
@@ -2,5 +2,8 @@
/* { dg-options "-pedantic" } */
double a = 1.dl; /* { dg-warning "decimal float" } */
+/* { dg-error "not supported for this target" "not supported" { target { ! dfp
} } .-1 } */
double b = 1.df; /* { dg-warning "decimal float" } */
+/* { dg-error "not supported for this target" "not supported" { target { ! dfp
} } .-1 } */
double c = 1.dd; /* { dg-warning "decimal float" } */
+/* { dg-error "not supported for this target" "not supported" { target { ! dfp
} } .-1 } */
Index: gcc/testsuite/gcc.dg/gnu2x-builtins-no-dfp-1.c
===================================================================
--- gcc/testsuite/gcc.dg/gnu2x-builtins-no-dfp-1.c (nonexistent)
+++ gcc/testsuite/gcc.dg/gnu2x-builtins-no-dfp-1.c (working copy)
@@ -0,0 +1,18 @@
+/* Test C2x built-in functions: test DFP built-in functions are not
+ available when no DFP support. Bug 91985. */
+/* { dg-do compile { target { ! dfp } } } */
+/* { dg-options "-std=gnu2x" } */
+
+int fabsd32 (void);
+int fabsd64 (void);
+int fabsd128 (void);
+int nand32 (void);
+int nand64 (void);
+int nand128 (void);
+
+__typeof__ (__builtin_fabsd32 (0)) d32; /* { dg-warning "implicit" } */
+__typeof__ (__builtin_fabsd64 (0)) d64; /* { dg-warning "implicit" } */
+__typeof__ (__builtin_fabsd128 (0)) d128; /* { dg-warning "implicit" } */
+__typeof__ (__builtin_nand32 (0)) d32n; /* { dg-warning "implicit" } */
+__typeof__ (__builtin_nand64 (0)) d64n; /* { dg-warning "implicit" } */
+__typeof__ (__builtin_nand128 (0)) d128n; /* { dg-warning "implicit" } */
Index: gcc/tree.c
===================================================================
--- gcc/tree.c (revision 278603)
+++ gcc/tree.c (working copy)
@@ -10334,23 +10334,26 @@ build_common_tree_nodes (bool signed_char)
uint64_type_node = make_or_reuse_type (64, 1);
/* Decimal float types. */
- dfloat32_type_node = make_node (REAL_TYPE);
- TYPE_PRECISION (dfloat32_type_node) = DECIMAL32_TYPE_SIZE;
- SET_TYPE_MODE (dfloat32_type_node, SDmode);
- layout_type (dfloat32_type_node);
- dfloat32_ptr_type_node = build_pointer_type (dfloat32_type_node);
+ if (targetm.decimal_float_supported_p ())
+ {
+ dfloat32_type_node = make_node (REAL_TYPE);
+ TYPE_PRECISION (dfloat32_type_node) = DECIMAL32_TYPE_SIZE;
+ SET_TYPE_MODE (dfloat32_type_node, SDmode);
+ layout_type (dfloat32_type_node);
+ dfloat32_ptr_type_node = build_pointer_type (dfloat32_type_node);
- dfloat64_type_node = make_node (REAL_TYPE);
- TYPE_PRECISION (dfloat64_type_node) = DECIMAL64_TYPE_SIZE;
- SET_TYPE_MODE (dfloat64_type_node, DDmode);
- layout_type (dfloat64_type_node);
- dfloat64_ptr_type_node = build_pointer_type (dfloat64_type_node);
+ dfloat64_type_node = make_node (REAL_TYPE);
+ TYPE_PRECISION (dfloat64_type_node) = DECIMAL64_TYPE_SIZE;
+ SET_TYPE_MODE (dfloat64_type_node, DDmode);
+ layout_type (dfloat64_type_node);
+ dfloat64_ptr_type_node = build_pointer_type (dfloat64_type_node);
- dfloat128_type_node = make_node (REAL_TYPE);
- TYPE_PRECISION (dfloat128_type_node) = DECIMAL128_TYPE_SIZE;
- SET_TYPE_MODE (dfloat128_type_node, TDmode);
- layout_type (dfloat128_type_node);
- dfloat128_ptr_type_node = build_pointer_type (dfloat128_type_node);
+ dfloat128_type_node = make_node (REAL_TYPE);
+ TYPE_PRECISION (dfloat128_type_node) = DECIMAL128_TYPE_SIZE;
+ SET_TYPE_MODE (dfloat128_type_node, TDmode);
+ layout_type (dfloat128_type_node);
+ dfloat128_ptr_type_node = build_pointer_type (dfloat128_type_node);
+ }
complex_integer_type_node = build_complex_type (integer_type_node, true);
complex_float_type_node = build_complex_type (float_type_node, true);
--
Joseph S. Myers
[email protected]
