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Fix latent bug in optabs
- From: Josef Zlomek <zlomj9am at artax dot karlin dot mff dot cuni dot cz>
- To: gcc-patches at gcc dot gnu dot org
- Date: Sun, 5 Jan 2003 16:18:05 +0100
- Subject: Fix latent bug in optabs
Hi,
when emiting a libcall whose parameter is large
(for example "struct { unsigned char b[128]; } bitvec;" )
the loop is created to copy the parameter.
When compiling my testcase, the REG_LIBCALL note was tried to attach to
NOTE_INSN_LOOP_BEG which of course did not success and the missing
REG_LIBCALL note caused a segfault in gcse.
However if the REG_LIBCALL note was attached to some "normal" instruction
it would be wrong because the block between REG_LIBCALL and REG_RETVAL
must be in a single basic block
but the loop copying the parameters was inside too.
This patch checks whether the insns between REG_LIBCALL and REG_RETVAL
will be contained in a single basic block (by checking whether all
instructions are not control_flow_insn_p) and
if the insns will not be in a single basic block
the REG_LIBCALL and REG_RETVAL notes will not be emitted.
This fixes the problem with a source which made gcse to segfault.
Bootstrapped/regtested mainline i386 (athlon).
OK for mainline and 3_3-branch?
Josef
Sun Jan 5 15:47:06 CET 2003 Josef Zlomek <zlomj9am@artax.karlin.mff.cuni.cz>
* Makefile.in (optabs.o): Add dependencies on basic-block.h and
hard-reg-set.h.
* basic-block.h (control_flow_insn_p): Fuction was exported.
* cfgbuild.c (control_flow_insn_p): Fuction was made non-static.
* optabs.c (emit_libcall_block): Emit REG_LIBCALL and REG_RETVAL
notes only when the region is contained in a single basic block.
Index: Makefile.in
===================================================================
RCS file: /cvs/gcc/gcc/gcc/Makefile.in,v
retrieving revision 1.961
diff -u -c -3 -p -r1.961 Makefile.in
*** Makefile.in 19 Dec 2002 15:53:46 -0000 1.961
--- Makefile.in 5 Jan 2003 15:08:15 -0000
*************** explow.o : explow.c $(CONFIG_H) $(SYSTEM
*** 1460,1466 ****
toplev.h function.h ggc.h $(TM_P_H) gt-explow.h
optabs.o : optabs.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) $(TREE_H) \
flags.h insn-config.h $(EXPR_H) $(OPTABS_H) libfuncs.h $(RECOG_H) reload.h \
! toplev.h $(GGC_H) real.h $(TM_P_H) except.h gt-optabs.h
dbxout.o : dbxout.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(TREE_H) $(RTL_H) \
flags.h $(REGS_H) debug.h $(TM_P_H) $(TARGET_H) function.h langhooks.h \
insn-config.h reload.h gstab.h xcoffout.h output.h dbxout.h toplev.h
--- 1460,1467 ----
toplev.h function.h ggc.h $(TM_P_H) gt-explow.h
optabs.o : optabs.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) $(TREE_H) \
flags.h insn-config.h $(EXPR_H) $(OPTABS_H) libfuncs.h $(RECOG_H) reload.h \
! toplev.h $(GGC_H) real.h $(TM_P_H) except.h gt-optabs.h hard-reg-set.h \
! $(BASIC_BLOCK_H)
dbxout.o : dbxout.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(TREE_H) $(RTL_H) \
flags.h $(REGS_H) debug.h $(TM_P_H) $(TARGET_H) function.h langhooks.h \
insn-config.h reload.h gstab.h xcoffout.h output.h dbxout.h toplev.h
Index: basic-block.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/basic-block.h,v
retrieving revision 1.163
diff -u -c -3 -p -r1.163 basic-block.h
*** basic-block.h 19 Dec 2002 02:59:15 -0000 1.163
--- basic-block.h 5 Jan 2003 15:08:16 -0000
*************** extern void fixup_abnormal_edges PARAMS
*** 805,810 ****
--- 805,811 ----
extern bool can_hoist_insn_p PARAMS ((rtx, rtx, regset));
extern rtx hoist_insn_after PARAMS ((rtx, rtx, rtx, rtx));
extern rtx hoist_insn_to_edge PARAMS ((rtx, edge, rtx, rtx));
+ extern bool control_flow_insn_p PARAMS ((rtx));
/* In dominance.c */
Index: cfgbuild.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cfgbuild.c,v
retrieving revision 1.29
diff -u -c -3 -p -r1.29 cfgbuild.c
*** cfgbuild.c 16 Dec 2002 18:19:06 -0000 1.29
--- cfgbuild.c 5 Jan 2003 15:08:16 -0000
*************** static void make_eh_edge PARAMS ((sbitm
*** 59,65 ****
static void find_bb_boundaries PARAMS ((basic_block));
static void compute_outgoing_frequencies PARAMS ((basic_block));
static bool inside_basic_block_p PARAMS ((rtx));
- static bool control_flow_insn_p PARAMS ((rtx));
/* Return true if insn is something that should be contained inside basic
block. */
--- 59,64 ----
*************** inside_basic_block_p (insn)
*** 97,103 ****
/* Return true if INSN may cause control flow transfer, so it should be last in
the basic block. */
! static bool
control_flow_insn_p (insn)
rtx insn;
{
--- 96,102 ----
/* Return true if INSN may cause control flow transfer, so it should be last in
the basic block. */
! bool
control_flow_insn_p (insn)
rtx insn;
{
Index: optabs.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/optabs.c,v
retrieving revision 1.154
diff -u -c -3 -p -r1.154 optabs.c
*** optabs.c 16 Dec 2002 18:19:44 -0000 1.154
--- optabs.c 5 Jan 2003 15:08:16 -0000
*************** Software Foundation, 59 Temple Place - S
*** 42,47 ****
--- 42,49 ----
#include "reload.h"
#include "ggc.h"
#include "real.h"
+ #include "hard-reg-set.h"
+ #include "basic-block.h"
/* Each optab contains info on how this target machine
can perform a particular operation
*************** emit_libcall_block (insns, target, resul
*** 3309,3318 ****
/* Encapsulate the block so it gets manipulated as a unit. */
if (!flag_non_call_exceptions || !may_trap_p (equiv))
{
! REG_NOTES (first) = gen_rtx_INSN_LIST (REG_LIBCALL, last,
! REG_NOTES (first));
! REG_NOTES (last) = gen_rtx_INSN_LIST (REG_RETVAL, first,
! REG_NOTES (last));
}
}
--- 3311,3336 ----
/* Encapsulate the block so it gets manipulated as a unit. */
if (!flag_non_call_exceptions || !may_trap_p (equiv))
{
! /* We can't attach the REG_LIBCALL and REG_RETVAL notes
! when the encapsulated region would not be in one basic block,
! i.e. when there is a control_flow_insn_p insn between FIRST and LAST.
! */
! bool attach_libcall_retval_notes = true;
! next = NEXT_INSN (last);
! for (insn = first; insn != next; insn = NEXT_INSN (insn))
! if (control_flow_insn_p (insn))
! {
! attach_libcall_retval_notes = false;
! break;
! }
!
! if (attach_libcall_retval_notes)
! {
! REG_NOTES (first) = gen_rtx_INSN_LIST (REG_LIBCALL, last,
! REG_NOTES (first));
! REG_NOTES (last) = gen_rtx_INSN_LIST (REG_RETVAL, first,
! REG_NOTES (last));
! }
}
}