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Fix profile_count::apply_probability

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profile_count::apply_probability misses check for uninitialized probability which leads
to completely random results on applying uninitialized probability to initialized scale.
This can make difference when i.e. inlining -fno-guess-branch-probability function
to -fguess-branch-probability one.

gcc/ChangeLog:

	* profile-count.h (profile_count::apply_probability): Fix
	handling of uninitialized probabilities, optimize scaling
	by probability 1.
This commit is contained in:
Jan Hubicka 2023-07-27 15:57:54 +02:00
parent d1c072a1c3
commit 499b8079a6
1 changed files with 2 additions and 2 deletions
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4
gcc/profile-count.h
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@ -1129,11 +1129,11 @@ public:
/* Scale counter according to PROB. */
profile_count apply_probability (profile_probability prob) const
{
if (*this == zero ())
if (*this == zero () || prob == profile_probability::always ())
return *this;
if (prob == profile_probability::never ())
return zero ();
if (!initialized_p ())
if (!initialized_p () || !prob.initialized_p ())
return uninitialized ();
profile_count ret;
uint64_t tmp;