[Bug debug/88882] gcc generates wrong debug information at -O1
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=2 Bug 2 depends on bug 89892, which changed state. Bug 89892 Summary: gcc generates wrong debug information at -O2 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89892 What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED
[Bug debug/88882] gcc generates wrong debug information at -O1
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=2 Richard Biener changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |DUPLICATE --- Comment #4 from Richard Biener --- . *** This bug has been marked as a duplicate of bug 89892 ***
[Bug debug/88882] gcc generates wrong debug information at -O1
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=2 Richard Biener changed: What|Removed |Added Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org
[Bug debug/88882] gcc generates wrong debug information at -O1
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=2 Richard Biener changed: What|Removed |Added Depends on||89892 --- Comment #3 from Richard Biener --- Really a duplicate as well. Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89892 [Bug 89892] gcc generates wrong debug information at -O2
[Bug debug/88882] gcc generates wrong debug information at -O1
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=2 --- Comment #2 from Qirun Zhang --- Bisection points to r216247.
[Bug debug/88882] gcc generates wrong debug information at -O1
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=2
Richard Biener changed:
What|Removed |Added
Keywords||wrong-debug
Status|UNCONFIRMED |NEW
Last reconfirmed||2019-01-17
Version|unknown |9.0
Ever confirmed|0 |1
--- Comment #1 from Richard Biener ---
The fact that l == 2 initially has been completely elided in the IL without
retaining a # DEBUG l = NULL. CCP does this when the basic-block containing
the debug stmts is elided.
+Removing basic block 4
main ()
{
int l;
@@ -8,7 +9,6 @@
int c.1_2;
int _3;
int c.2_4;
- int _11;
:
# DEBUG BEGIN_STMT
@@ -19,35 +19,27 @@
if (b.0_1 != 0)
goto ; [INV]
else
-goto ; [INV]
+goto ; [INV]
:
# DEBUG BEGIN_STMT
- l_7 = 2;
- # DEBUG l => l_7
- # DEBUG BEGIN_STMT
- goto ; [INV]
-
- :
- # DEBUG BEGIN_STMT
optimize_me_not ();
Or rather it is likely CFG cleanup which is faced with
:
# DEBUG BEGIN_STMT
b.0_1 = b;
if (b.0_1 != 0)
goto ; [INV]
else
goto ; [INV]
:
# DEBUG BEGIN_STMT
# DEBUG l => 2
# DEBUG BEGIN_STMT
goto ; [INV]
:
c.2_4 = c;
if (c.2_4 <= 1)
goto ; [INV]
else
goto ; [INV]
note how it cannot move the debug stmts to neither the predecessor nor
the successor but it has to elide the forwarder for compare-debug
reasons. If we knew that l didn't have a value before we could have
moved it to the predecessor though.
Hard one.
Well - allow DEBUG stmts on edges ;)
