Additional _BitInt test coverage [PR102989]

On Tue, Sep 05, 2023 at 10:40:26PM +0000, Joseph Myers wrote:
> Additional tests I think should be added (for things I expect should
> already work):
>
> * Tests for BITINT_MAXWIDTH in <limits.h>.  Test that it's defined for
> C2x, but not defined for C11/C17 (the latter independent of whether the
> target has _BitInt support).  Test the value as well: _BitInt
> (BITINT_MAXWIDTH) should be OK (both signed and unsigned) but _BitInt
> (BITINT_MAXWIDTH + 1) should not be OK.  Also test that BITINT_MAXWIDTH >=
> ULLONG_MAX.
>
> * Test _BitInt (N) where N is a constexpr variable or enum constant (I
> expect these should work - the required call to convert_lvalue_to_rvalue
> for constexpr to work is present - but I don't see such tests in the
> testsuite).
>
> * Test that -funsigned-bitfields does not affect the signedness of _BitInt
> (N) bit-fields (the standard wording isn't entirely clear, but that's
> what's implemented in the patches).
>
> * Test the errors for _Sat used with _BitInt (though such a test might not
> actually run at present because no target supports both features).

The following patch does that plus for most of the new changes in the
C _BitInt support patch requested in patch review it also does testsuite
coverage.

2023-09-06  Jakub Jelinek  <jakub@redhat.com>

	PR c/102989
	* gcc.dg/bitint-2.c (foo): Add tests for constexpr var or enumerator
	arguments of _BitInt.
	* gcc.dg/bitint-31.c: Remove forgotten 0 &&.
	* gcc.dg/bitint-32.c: New test.
	* gcc.dg/bitint-33.c: New test.
	* gcc.dg/bitint-34.c: New test.
	* gcc.dg/bitint-35.c: New test.
	* gcc.dg/bitint-36.c: New test.
	* gcc.dg/fixed-point/bitint-1.c: New test.

8 files changed, 132 insertions, 1 deletions

diff --git a/gcc/testsuite/gcc.dg/bitint-2.c b/gcc/testsuite/gcc.dg/bitint-2.c
index 4b639ed..6fa9c06 100644
--- a/gcc/testsuite/gcc.dg/bitint-2.c
+++ b/gcc/testsuite/gcc.dg/bitint-2.c
@@ -14,6 +14,10 @@ foo (void)
   _BitInt(5) unsigned d = (unsigned _BitInt(5)) 4;
   _BitInt(32) e = (_BitInt(32)) 5;
   _BitInt(32) unsigned f = (unsigned _BitInt(32)) 6;
+  constexpr int g = 43;
+  enum E { F = 44 };
+  _BitInt(g) h;
+  unsigned _BitInt(F) i;
   static_assert (expr_has_type (a, signed _BitInt(42)), "");
   static_assert (expr_has_type (a, _BitInt(42)), "");
   static_assert (!expr_has_type (a, unsigned _BitInt(42)), "");
@@ -66,6 +70,8 @@ foo (void)
   static_assert (expr_has_type (-1UWB, unsigned _BitInt(1)), "");
   static_assert (expr_has_type (1uWB, unsigned _BitInt(1)), "");
   static_assert (expr_has_type (2Uwb, unsigned _BitInt(2)), "");
+  static_assert (expr_has_type (h, signed _BitInt(43)), "");
+  static_assert (expr_has_type (i, unsigned _BitInt(44)), "");
   static_assert (0wb == 0, "");
   static_assert (-1wb == -1, "");
   static_assert (0xffffffffwb == 4294967295wb, "");
diff --git a/gcc/testsuite/gcc.dg/bitint-31.c b/gcc/testsuite/gcc.dg/bitint-31.c
index 4d29146..65ac271 100644
--- a/gcc/testsuite/gcc.dg/bitint-31.c
+++ b/gcc/testsuite/gcc.dg/bitint-31.c
@@ -255,7 +255,7 @@ main ()
   check_round (testfltu_192 (340282356779733661637539395458142568448uwb), __builtin_inff (), 0xffffffp+104f, __builtin_inff (), 0xffffffp+104f);
   check_round (testfltu_192 (6277101735386680763835789423207666416102355444464034512895uwb), __builtin_inff (), 0xffffffp+104f, __builtin_inff (), 0xffffffp+104f);
 #endif
-#if 0 && __BITINT_MAXWIDTH__ >= 575
+#if __BITINT_MAXWIDTH__ >= 575
   check_round (testflt_575 (10633823015541376812058405359715352575wb), 0xfffffep+99f, 0xfffffep+99f, 0xffffffp+99f, 0xfffffep+99f);
   check_round (testflt_575 (10633823015541376812058405359715352576wb), 0xfffffep+99f, 0xfffffep+99f, 0xffffffp+99f, 0xfffffep+99f);
   check_round (testflt_575 (10633823015541376812058405359715352577wb), 0xffffffp+99f, 0xfffffep+99f, 0xffffffp+99f, 0xfffffep+99f);
diff --git a/gcc/testsuite/gcc.dg/bitint-32.c b/gcc/testsuite/gcc.dg/bitint-32.c
new file mode 100644
index 0000000..e6c277e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/bitint-32.c
@@ -0,0 +1,14 @@
+/* PR c/102989 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-std=c2x" } */
+
+#include <limits.h>
+
+#ifndef BITINT_MAXWIDTH
+#error BITINT_MAXWIDTH not defined
+#elif BITINT_MAXWIDTH < ULLONG_WIDTH
+#error BITINT_MAXWIDTH smaller than ULLONG_WIDTH
+#endif
+
+_BitInt(BITINT_MAXWIDTH) a;
+_BitInt(BITINT_MAXWIDTH + 1) b;		/* { dg-error "'_BitInt' argument '\[0-9]+' is larger than 'BITINT_MAXWIDTH' '\[0-9]+'" } */
diff --git a/gcc/testsuite/gcc.dg/bitint-33.c b/gcc/testsuite/gcc.dg/bitint-33.c
new file mode 100644
index 0000000..a46d53e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/bitint-33.c
@@ -0,0 +1,9 @@
+/* PR c/102989 */
+/* { dg-do compile } */
+/* { dg-options "-std=c17" } */
+
+#include <limits.h>
+
+#ifdef BITINT_MAXWIDTH
+#error BITINT_MAXWIDTH defined in C11
+#endif
diff --git a/gcc/testsuite/gcc.dg/bitint-34.c b/gcc/testsuite/gcc.dg/bitint-34.c
new file mode 100644
index 0000000..7eaadb2
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/bitint-34.c
@@ -0,0 +1,16 @@
+/* PR c/102989 */
+/* Test that -funsigned-bitfields doesn't affect _BitInt bit-fields which are always signed.  */
+/* { dg-do run { target bitint } } */
+/* { dg-options "-std=c2x -funsigned-bitfields" } */
+
+struct S { _BitInt(22) a : 7; signed _BitInt(22) b : 7; unsigned _BitInt(22) c : 7; } s;
+
+int
+main ()
+{
+  s.a = -64;
+  s.b = -64;
+  s.c = -64;
+  if (s.a != -64 || s.b != -64 || s.c != 64)
+    __builtin_abort ();
+}
diff --git a/gcc/testsuite/gcc.dg/bitint-35.c b/gcc/testsuite/gcc.dg/bitint-35.c
new file mode 100644
index 0000000..352633d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/bitint-35.c
@@ -0,0 +1,37 @@
+/* PR c/102989 */
+/* { dg-do compile { target { bitint && { float32 && int32 } } } } */
+/* { dg-options "-std=c2x -Wconversion -Wfloat-conversion" } */
+/* { dg-add-options float32 } */
+
+void
+foo (_Float32 x)
+{
+  _BitInt(57) a = 1.5F32;				/* { dg-warning "conversion from '_Float32' to '_BitInt\\\(57\\\)' changes value from '1.5e\\\+0f32' to '1'" } */
+  _BitInt(27) b = 76117358uwb;				/* { dg-warning "signed conversion from 'unsigned _BitInt\\\(27\\\)' to '_BitInt\\\(27\\\)' changes value from '76117358' to '-58100370'" } */
+  unsigned _BitInt(27) c = -15wb;			/* { dg-warning "unsigned conversion from '_BitInt\\\(5\\\)' to 'unsigned _BitInt\\\(27\\\)' changes value from '-15' to '134217713'" } */
+  _BitInt(27) d = -390288573wb;				/* { dg-warning "overflow in conversion from '_BitInt\\\(30\\\)' to '_BitInt\\\(27\\\)' changes value from '-390288573' to '12364611'" } */
+  unsigned _BitInt(27) e = 309641337uwb;		/* { dg-warning "conversion from 'unsigned _BitInt\\\(29\\\)' to 'unsigned _BitInt\\\(27\\\)' changes value from '309641337' to '41205881'" } */
+  _BitInt(27) f = 76117358U;				/* { dg-warning "signed conversion from 'unsigned int' to '_BitInt\\\(27\\\)' changes value from '76117358' to '-58100370'" } */
+  unsigned _BitInt(27) g = -15;				/* { dg-warning "unsigned conversion from 'int' to 'unsigned _BitInt\\\(27\\\)' changes value from '-15' to '134217713'" } */
+  _BitInt(27) h = -390288573;				/* { dg-warning "overflow in conversion from 'int' to '_BitInt\\\(27\\\)' changes value from '-390288573' to '12364611'" } */
+  unsigned _BitInt(27) i = 309641337U;			/* { dg-warning "conversion from 'unsigned int' to 'unsigned _BitInt\\\(27\\\)' changes value from '309641337' to '41205881'" } */
+  int j = 2936216298uwb;				/* { dg-warning "signed conversion from 'unsigned _BitInt\\\(32\\\)' to 'int' changes value from '2936216298' to '-1358750998'" } */
+  unsigned int k = -15wb;				/* { dg-warning "unsigned conversion from '_BitInt\\\(5\\\)' to 'unsigned int' changes value from '-15' to '4294967281'" } */
+  int l = -8087431137529383656wb;			/* { dg-warning "overflow in conversion from '_BitInt\\\(64\\\)' to 'int' changes value from '-8087431137529383656' to '-1105152744'" } */
+  unsigned int m = 1664073919553255778uwb;		/* { dg-warning "conversion from 'unsigned _BitInt\\\(61\\\)' to 'unsigned int' changes value from '1664073919553255778' to '3338058082'" } */
+#if __BITINT_MAXWIDTH__ >= 575
+  _Float32 n = 51441631083309184313435496923626431699697406185384986811300218556561965470218425783308778801748592322915101142266821623326688106425864884688172114173397118407357447763009120wb;	/* { dg-warning "conversion from '_BitInt\\\(575\\\)' to '_Float32' changes value from '0x353eab28b46b03ea99b84f9736cd8dbe5e986915a0383c3cb381c0da41e31b3621c75fd53262bfcb1b0e6251dbf00f3988784e29b08b65640c263e4d0959832a20e2ff5245be1e60' to '\\\+Inff32'" "" { target bitint575 } } */
+#endif
+  _BitInt(57) o = x;					/* { dg-warning "conversion from '_Float32' to '_BitInt\\\(57\\\)' may change value" } */
+  unsigned _BitInt(15) p = 32767uwb;
+  unsigned _BitInt(15) q = (_BitInt(42)) p;
+  _BitInt(17) r = 0;
+  _BitInt(17) s = ((_BitInt(42)) r) & 32767wb;
+#if __BITINT_MAXWIDTH__ >= 575
+  _BitInt(575) t = 0;
+  _Float32 u = t;					/* { dg-warning "conversion from '_BitInt\\\(575\\\)' to '_Float32' may change value" "" { target bitint575 } } */
+#endif
+  _BitInt(42) v = 0;
+  unsigned _BitInt(17) w = v;				/* { dg-warning "conversion from '_BitInt\\\(42\\\)' to 'unsigned _BitInt\\\(17\\\)' may change value" } */
+  _BitInt(17) y = v;					/* { dg-warning "conversion from '_BitInt\\\(42\\\)' to '_BitInt\\\(17\\\)' may change value" } */
+}
diff --git a/gcc/testsuite/gcc.dg/bitint-36.c b/gcc/testsuite/gcc.dg/bitint-36.c
new file mode 100644
index 0000000..1912869
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/bitint-36.c
@@ -0,0 +1,39 @@
+/* PR c/102989 */
+/* { dg-do compile { target { bitint } } } */
+/* { dg-options "-std=c2x -Wint-in-bool-context -Waddress -Wpointer-to-int-cast -Wint-to-pointer-cast -Wint-conversion -Wshift-negative-value -Wshift-count-overflow -Wdiv-by-zero" } */
+
+extern char *ax[];
+
+void bar (int);
+
+void
+foo (_BitInt(61) x, long long *y)
+{
+  if (x << 15)						/* { dg-warning "'<<' in boolean context, did you mean '<'" } */
+    ;
+  bar ((_BitInt(sizeof (void *) * __CHAR_BIT__)) (ax + 0) == 0);
+  bar ((unsigned _BitInt(sizeof (void *) * __CHAR_BIT__)) (ax + 1) == 0);
+  char *z = __builtin_assume_aligned (y, 32wb, 8wb);
+  *z = 42;
+  _BitInt(sizeof (void *) * __CHAR_BIT__ + 1) a = (_BitInt(sizeof (void *) * __CHAR_BIT__ + 1)) y;			/* { dg-warning "cast from pointer to integer of different size" } */
+  unsigned _BitInt(sizeof (void *) * __CHAR_BIT__ + 1) b = (unsigned _BitInt(sizeof (void *) * __CHAR_BIT__ + 1)) y;	/* { dg-warning "cast from pointer to integer of different size" } */
+  _BitInt(sizeof (void *) * __CHAR_BIT__ - 1) c = (_BitInt(sizeof (void *) * __CHAR_BIT__ - 1)) y;			/* { dg-warning "cast from pointer to integer of different size" } */
+  unsigned _BitInt(sizeof (void *) * __CHAR_BIT__ - 1) d = (unsigned _BitInt(sizeof (void *) * __CHAR_BIT__ - 1)) y;	/* { dg-warning "cast from pointer to integer of different size" } */
+  void *e = (void *) a;					/* { dg-warning "cast to pointer from integer of different size" } */
+  void *f = (void *) b;					/* { dg-warning "cast to pointer from integer of different size" } */
+  void *g = (void *) c;					/* { dg-warning "cast to pointer from integer of different size" } */
+  void *h = (void *) d;					/* { dg-warning "cast to pointer from integer of different size" } */
+  a = y;						/* { dg-warning "assignment to '_BitInt\\\(\[0-9]+\\\)' from 'long long int \\\*' makes integer from pointer without a cast" } */
+  b = y;						/* { dg-warning "assignment to 'unsigned _BitInt\\\(\[0-9]+\\\)' from 'long long int \\\*' makes integer from pointer without a cast" } */
+  c = y;						/* { dg-warning "assignment to '_BitInt\\\(\[0-9]+\\\)' from 'long long int \\\*' makes integer from pointer without a cast" } */
+  d = y;						/* { dg-warning "assignment to 'unsigned _BitInt\\\(\[0-9]+\\\)' from 'long long int \\\*' makes integer from pointer without a cast" } */
+  e = a;						/* { dg-warning "assignment to 'void \\\*' from '_BitInt\\\(\[0-9]+\\\)' makes pointer from integer without a cast" } */
+  f = b;						/* { dg-warning "assignment to 'void \\\*' from 'unsigned _BitInt\\\(\[0-9]+\\\)' makes pointer from integer without a cast" } */
+  g = c;						/* { dg-warning "assignment to 'void \\\*' from '_BitInt\\\(\[0-9]+\\\)' makes pointer from integer without a cast" } */
+  h = d;						/* { dg-warning "assignment to 'void \\\*' from 'unsigned _BitInt\\\(\[0-9]+\\\)' makes pointer from integer without a cast" } */
+  _BitInt(61) i = (1wb - 1152921504606846975wb) << 1;	/* { dg-warning "left shift of negative value" } */
+							/* { dg-warning "result of '-1152921504606846974 << 1' requires 62 bits to represent, but '_BitInt\\\(61\\\)' only has 61 bits" "" { target *-*-* } .-1 } */
+  _BitInt(61) j = i << (60 + 1);			/* { dg-warning "left shift count >= width of type" } */
+  _BitInt(61) k = i >> (60 + 1);			/* { dg-warning "right shift count >= width of type" } */
+  _BitInt(61) l = i / (51wb - 51wb);			/* { dg-warning "division by zero" } */
+}
diff --git a/gcc/testsuite/gcc.dg/fixed-point/bitint-1.c b/gcc/testsuite/gcc.dg/fixed-point/bitint-1.c
new file mode 100644
index 0000000..de525ad
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/fixed-point/bitint-1.c
@@ -0,0 +1,10 @@
+/* PR c/102989 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-std=c2x" } */
+
+void
+foo (void)
+{
+  _Sat _BitInt (42) a;		/* { dg-error "both '_Sat' and '_BitInt' in declaration specifiers" } */
+  _BitInt (42) _Sat b;		/* { dg-error "both '_Sat' and '_BitInt' in declaration specifiers" } */
+}