diff options
Diffstat (limited to 'patches/gcc/4.0.0/pr20973-fix.patch')
| -rw-r--r-- | patches/gcc/4.0.0/pr20973-fix.patch | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/patches/gcc/4.0.0/pr20973-fix.patch b/patches/gcc/4.0.0/pr20973-fix.patch new file mode 100644 index 0000000..7451219 --- /dev/null +++ b/patches/gcc/4.0.0/pr20973-fix.patch @@ -0,0 +1,80 @@ +http://gcc.gnu.org/PR20973 + +"gcc 4 (about RC1) miscompiles khtml, in fact something in CSS, which basically +leads to all websites being misrendered. I can't easily reduce the testcase, +but have applied the whole preprocessed source of css/cssstyleselector.ii. + +It is to be compiled with g++ -O2 -fPIC -march=i586 -mtune=i686 +-fno-exceptions. A more detailed analysis will follow, as we've found out +some things already." + +--- + +Subject: Bug 20973 + +CVSROOT: /cvs/gcc +Module name: gcc +Branch: gcc-4_0-branch +Changes by: matz@gcc.gnu.org 2005-04-22 17:30:21 + +Modified files: + gcc : ChangeLog reload.c + +Log message: + PR middle-end/20973 + * reload.c (push_reload, find_dummy_reload): Check for uninitialized + pseudos. + +Patches: +http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=2.7592.2.177&r2=2.7592.2.178 +http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/reload.c.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.268&r2=1.268.2.1 + +--- + +=================================================================== +RCS file: /cvs/gcc/gcc/gcc/reload.c,v +retrieving revision 1.268 +retrieving revision 1.268.2.1 +diff -u -r1.268 -r1.268.2.1 +--- gcc/gcc/reload.c 2005/02/24 22:06:06 1.268 ++++ gcc/gcc/reload.c 2005/04/22 17:30:15 1.268.2.1 +@@ -1520,7 +1520,7 @@ + But if there is no spilling in this block, that is OK. + An explicitly used hard reg cannot be a spill reg. */ + +- if (rld[i].reg_rtx == 0 && in != 0) ++ if (rld[i].reg_rtx == 0 && in != 0 && hard_regs_live_known) + { + rtx note; + int regno; +@@ -1534,6 +1534,11 @@ + && REG_P (XEXP (note, 0)) + && (regno = REGNO (XEXP (note, 0))) < FIRST_PSEUDO_REGISTER + && reg_mentioned_p (XEXP (note, 0), in) ++ /* Check that we don't use a hardreg for an uninitialized ++ pseudo. See also find_dummy_reload(). */ ++ && (ORIGINAL_REGNO (XEXP (note, 0)) < FIRST_PSEUDO_REGISTER ++ || ! bitmap_bit_p (ENTRY_BLOCK_PTR->global_live_at_end, ++ ORIGINAL_REGNO (XEXP (note, 0)))) + && ! refers_to_regno_for_reload_p (regno, + (regno + + hard_regno_nregs[regno] +@@ -1997,7 +2002,17 @@ + is a subreg, and in that case, out + has a real mode. */ + (GET_MODE (out) != VOIDmode +- ? GET_MODE (out) : outmode))) ++ ? GET_MODE (out) : outmode)) ++ /* But only do all this if we can be sure, that this input ++ operand doesn't correspond with an uninitialized pseudoreg. ++ global can assign some hardreg to it, which is the same as ++ a different pseudo also currently live (as it can ignore the ++ conflict). So we never must introduce writes to such hardregs, ++ as they would clobber the other live pseudo using the same. ++ See also PR20973. */ ++ && (ORIGINAL_REGNO (in) < FIRST_PSEUDO_REGISTER ++ || ! bitmap_bit_p (ENTRY_BLOCK_PTR->global_live_at_end, ++ ORIGINAL_REGNO (in)))) + { + unsigned int regno = REGNO (in) + in_offset; + unsigned int nwords = hard_regno_nregs[regno][inmode]; |