[Bug debug/105158] ftree-ccp (CFG cleanup) drops DWARF const value attribute at -Og/-O1/-O2/-O3
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105158 Andrew Pinski changed: What|Removed |Added Target Milestone|--- |13.0
[Bug debug/105158] ftree-ccp (CFG cleanup) drops DWARF const value attribute at -Og/-O1/-O2/-O3
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105158 Richard Biener changed: What|Removed |Added Resolution|--- |FIXED Status|ASSIGNED|RESOLVED --- Comment #6 from Richard Biener --- Fixed.
[Bug debug/105158] ftree-ccp (CFG cleanup) drops DWARF const value attribute at -Og/-O1/-O2/-O3
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105158 --- Comment #5 from CVS Commits --- The master branch has been updated by Richard Biener : https://gcc.gnu.org/g:1ba68f78c9d2510eb095f7d8a90c87cd5fd4183d commit r13-99-g1ba68f78c9d2510eb095f7d8a90c87cd5fd4183d Author: Richard Biener Date: Tue Apr 5 15:23:54 2022 +0200 debug/105158 - improve debug stmt retaining for forwarder removal Currently when we cannot move debug stmt from a forwarder to the destination block we drop/reset them. But in some cases as for the testcase we can move them to the predecessor when that has a single successor and we can insert after the last stmt of the block. That allows us to preserve debug info here. 2022-04-05 Richard Biener PR debug/105158 * tree-cfgcleanup.cc (move_debug_stmts_from_forwarder): Move debug stmts to the predecessor if moving to the destination is not possible. (remove_forwarder_block): Adjust. (remove_forwarder_block_with_phi): Likewise.
[Bug debug/105158] ftree-ccp (CFG cleanup) drops DWARF const value attribute at -Og/-O1/-O2/-O3
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105158 --- Comment #4 from Richard Biener --- *** Bug 105194 has been marked as a duplicate of this bug. ***
[Bug debug/105158] ftree-ccp (CFG cleanup) drops DWARF const value attribute at -Og/-O1/-O2/-O3
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105158 --- Comment #3 from Richard Biener --- Created attachment 52748 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52748=edit patch
[Bug debug/105158] ftree-ccp (CFG cleanup) drops DWARF const value attribute at -Og/-O1/-O2/-O3
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105158 Richard Biener changed: What|Removed |Added Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org Status|NEW |ASSIGNED --- Comment #2 from Richard Biener --- I have a patch.
[Bug debug/105158] ftree-ccp (CFG cleanup) drops DWARF const value attribute at -Og/-O1/-O2/-O3
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105158 Richard Biener changed: What|Removed |Added Ever confirmed|0 |1 Status|UNCONFIRMED |NEW Summary|ftree-ccp drops DWARF const |ftree-ccp (CFG cleanup) |value attribute at |drops DWARF const value |-Og/-O1/-O2/-O3 |attribute at ||-Og/-O1/-O2/-O3 Severity|normal |enhancement Last reconfirmed||2022-04-05 --- Comment #1 from Richard Biener --- The issue is that the definition we put the debug stmt into is in : [t.c:4:5] # DEBUG BEGIN_STMT [t.c:4:16] # DEBUG l_174 => 0 [t.c:4:27] # DEBUG l_188 => 0 [t.c:4:38] # DEBUG l_191 => 0 [t.c:4:49] # DEBUG l_240 => 1 [t.c:5:5] # DEBUG BEGIN_STMT [t.c:6:5] # DEBUG BEGIN_STMT [t.c:6:20] # DEBUG l_169 => 0 [t.c:6:25] if (0 != 0) goto ; [INV] else goto ; [INV] : : [t.c:6:11] # DEBUG l_171 => 0 [t.c:7:5] # DEBUG BEGIN_STMT [t.c:7:5] goto ; [INV] : # l_169_3 = PHI <[t.c:6:20] 0(6), [t.c:7:30] l_169_19(7)> # DEBUG l_169 => l_169_3 [t.c:7:18] # DEBUG BEGIN_STMT [t.c:7:18] if (l_169_3 <= 9) goto ; [INV] else goto ; [INV] and when CFG cleanup merges all the forwarders it finds no location to put the debug stmt to - it tries to move the debug stmts to the successor but that doesn't have a single predecessor so that's not a valid thing to do. Moving to the predecessor would be valid if that has a single successor though but that's not implemented. In this case the predecessor is block 2 at the point in question and it has a single successor plus the last stmt in it doesn't end the BB.
