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re PR rtl-optimization/37489 (const_true_rtx returned for float compare)

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gcc/

2008-09-13  H.J. Lu  <hongjiu.lu@intel.com>

	PR rtl-optimization/37489
	* cse.c (fold_rtx): Don't return const_true_rtx for float
	compare if FLOAT_STORE_FLAG_VALUE is undefined.

gcc/testsuite/

2008-09-13  Raksit Ashok <raksit@google.com>

	PR rtl-optimization/37489
	* g++.dg/opt/cse3.C: New.

From-SVN: r140344
This commit is contained in:
H.J. Lu 2008-09-13 08:47:41 -07:00
parent 2deacb5e8a
commit 9e6a14a4ee
4 changed files with 80 additions and 5 deletions
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6
gcc/ChangeLog
View file

@ -1,3 +1,9 @@
2008-09-13 H.J. Lu <hongjiu.lu@intel.com>
PR rtl-optimization/37489
* cse.c (fold_rtx): Don't return const_true_rtx for float
compare if FLOAT_STORE_FLAG_VALUE is undefined.
2008-09-13 Jan Hubicka <jh@suse.cz>
PR tree-optimization/37392

26
gcc/cse.c
View file

@ -3214,17 +3214,24 @@ fold_rtx (rtx x, rtx insn)
if (const_arg0 == 0 || const_arg1 == 0)
{
struct table_elt *p0, *p1;
rtx true_rtx = const_true_rtx, false_rtx = const0_rtx;
rtx true_rtx, false_rtx;
enum machine_mode mode_arg1;
#ifdef FLOAT_STORE_FLAG_VALUE
if (SCALAR_FLOAT_MODE_P (mode))
{
#ifdef FLOAT_STORE_FLAG_VALUE
true_rtx = (CONST_DOUBLE_FROM_REAL_VALUE
(FLOAT_STORE_FLAG_VALUE (mode), mode));
#else
true_rtx = NULL_RTX;
#endif
false_rtx = CONST0_RTX (mode);
}
#endif
else
{
true_rtx = const_true_rtx;
false_rtx = const0_rtx;
}
code = find_comparison_args (code, &folded_arg0, &folded_arg1,
&mode_arg0, &mode_arg1);
@ -3332,8 +3339,17 @@ fold_rtx (rtx x, rtx insn)
const_arg1))
|| (REG_P (folded_arg1)
&& (REG_QTY (REGNO (folded_arg1)) == ent->comparison_qty))))
return (comparison_dominates_p (ent->comparison_code, code)
? true_rtx : false_rtx);
{
if (comparison_dominates_p (ent->comparison_code, code))
{
if (true_rtx)
return true_rtx;
else
break;
}
else
return false_rtx;
}
}
}
}

5
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,8 @@
2008-09-13 Raksit Ashok <raksit@google.com>
PR rtl-optimization/37489
* g++.dg/opt/cse3.C: New.
2008-09-13 H.J. Lu <hongjiu.lu@intel.com>
PR testsuite/37495

48
gcc/testsuite/g++.dg/opt/cse3.C Normal file
View file

@ -0,0 +1,48 @@
// This testcase resulted in invalid code generation on x86_64 targets
// due to a bug in fold_rtx. For a "true" value, fold_rtx represented it
// as const_true_rtx in floating-point mode, if the FLOAT_STORE_FLAG_VALUE
// macro is not defined.
// { dg-do run }
// { dg-options "-O1 -fno-guess-branch-probability -fcse-follow-jumps -fgcse -frerun-cse-after-loop" }
class StatVal {
public:
StatVal(double ev, double va)
: m(ev),
v(va) {}
StatVal(const StatVal& other)
: m(other.m),
v(other.v) {}
StatVal& operator*=(const StatVal& other) {
double A = m == 0 ? 1.0 : v / (m * m);
double B = other.m == 0 ? 1.0 : other.v / (other.m * other.m);
m = m * other.m;
v = m * m * (A + B);
return *this;
}
double m;
double v;
};
extern "C" void abort (void);
const StatVal two_dot_three(2, 0.3);
int main(int argc, char **argv) {
StatVal product3(two_dot_three);
product3 *= two_dot_three;
if (product3.v > 2.5)
{
abort();
}
return 0;
}