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x86_64: Fix compares with NaNs.

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Comparisons with unordered doubles was broken, NaNs always
compare unequal (and unordered) to everything, including
to itself.
This commit is contained in:
Michael Matz
2012-05-13 02:21:51 +02:00
parent 0394caf784
commit 2daae0dc99
2 changed files with 97 additions and 2 deletions
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66
tests/tcctest.c
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@ -87,6 +87,7 @@ void builtin_test(void);
void weak_test(void);
void global_data_test(void);
void cmp_comparison_test(void);
void math_cmp_test(void);
int fib(int n);
void num(int n);
@ -594,6 +595,7 @@ int main(int argc, char **argv)
weak_test();
global_data_test();
cmp_comparison_test();
math_cmp_test();
return 0;
}
@ -2592,3 +2594,67 @@ void cmp_comparison_test(void)
s.b2 = 0;
glob3 = 43;
compare_comparisons (&s);
return 0;
}
int fcompare (double a, double b, int code)
{
switch (code) {
case 0: return a == b;
case 1: return a != b;
case 2: return a < b;
case 3: return a >= b;
case 4: return a > b;
case 5: return a <= b;
}
}
void math_cmp_test(void)
{
double nan = 0.0/0.0;
double one = 1.0;
double two = 2.0;
int comp = 0;
#define bug(a,b,op,iop,part) printf("Test broken: %s %s %s %s %d\n", #a, #b, #op, #iop, part)
/* This asserts that "a op b" is _not_ true, but "a iop b" is true.
And it does this in various ways so that all code generation paths
are checked (generating inverted tests, or non-inverted tests, or
producing a 0/1 value without jumps (that's done in the fcompare
function). */
#define FCMP(a,b,op,iop,code) \
if (fcompare (a,b,code)) \
bug (a,b,op,iop,1); \
if (a op b) \
bug (a,b,op,iop,2); \
if (a iop b) \
; \
else \
bug (a,b,op,iop,3); \
if ((a op b) || comp) \
bug (a,b,op,iop,4); \
if ((a iop b) || comp) \
; \
else \
bug (a,b,op,iop,5);
/* Equality tests. */
FCMP(nan, nan, ==, !=, 0);
FCMP(one, two, ==, !=, 0);
FCMP(one, one, !=, ==, 1);
/* Non-equality is a bit special. */
if (!fcompare (nan, nan, 1))
bug (nan, nan, !=, ==, 6);
/* Relational tests on numbers. */
FCMP(two, one, <, >=, 2);
FCMP(one, two, >=, <, 3);
FCMP(one, two, >, <=, 4);
FCMP(two, one, <=, >, 5);
/* Relational tests on NaNs. Note that the inverse op here is
always !=, there's no operator in C that is equivalent to !(a < b),
when NaNs are involved, same for the other relational ops. */
FCMP(nan, nan, <, !=, 2);
FCMP(nan, nan, >=, !=, 3);
FCMP(nan, nan, >, !=, 4);