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author | Jakub Jelinek <jakub@redhat.com> | 2008-11-28 21:28:28 +0000 |
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committer | Jakub Jelinek <jakub@redhat.com> | 2008-11-28 21:28:28 +0000 |
commit | 395e83452153d1926f8231958ae4b421db952532 (patch) | |
tree | e1413c0e52e7a5c320b104608f69b283e6036142 /gas/ehopt.c | |
parent | 3aa3176b2dea5796ab968b289804eced655f07ee (diff) | |
download | gdb-395e83452153d1926f8231958ae4b421db952532.zip gdb-395e83452153d1926f8231958ae4b421db952532.tar.gz gdb-395e83452153d1926f8231958ae4b421db952532.tar.bz2 |
* Makefile.am (ehopt.o): Add struc-symbol.h.
* Makefile.in: Regenerated.
* ehopt.c: Include struc-symbol.h.
(check_eh_frame): For very small O_constant DW_CFA_advance_loc4
create correct DW_CFA_advance_loc. Handle O_subtract only
for code alignment factor 1, otherwise handle O_divide or
O_right_shift of O_subtract and O_constant.
(eh_frame_estimate_size_before_relax): Always divide by ca.
(eh_frame_convert_frag): Likewise.
* dw2gencfi.c (output_cfi_insn): Scale DW_CFA_advance_loc1,
DW_CFA_advance_loc2 and DW_CFA_advance_loc4 outputs.
Diffstat (limited to 'gas/ehopt.c')
-rw-r--r-- | gas/ehopt.c | 61 |
1 files changed, 39 insertions, 22 deletions
diff --git a/gas/ehopt.c b/gas/ehopt.c index 048bc57..323e27e 100644 --- a/gas/ehopt.c +++ b/gas/ehopt.c @@ -1,5 +1,6 @@ /* ehopt.c--optimize gcc exception frame information. - Copyright 1998, 2000, 2001, 2003, 2005, 2007 Free Software Foundation, Inc. + Copyright 1998, 2000, 2001, 2003, 2005, 2007, 2008 + Free Software Foundation, Inc. Written by Ian Lance Taylor <ian@cygnus.com>. This file is part of GAS, the GNU Assembler. @@ -21,6 +22,7 @@ #include "as.h" #include "subsegs.h" +#include "struc-symbol.h" /* We include this ELF file, even though we may not be assembling for ELF, since the exception frame information is always in a format @@ -398,13 +400,10 @@ check_eh_frame (expressionS *exp, unsigned int *pnbytes) subtracted were in the same frag and the expression was reduced to a constant. We can do the optimization entirely in this function. */ - if (d->cie_info.code_alignment > 0 - && exp->X_add_number % d->cie_info.code_alignment == 0 - && exp->X_add_number / d->cie_info.code_alignment < 0x40) + if (exp->X_add_number < 0x40) { d->loc4_frag->fr_literal[d->loc4_fix] - = DW_CFA_advance_loc - | (exp->X_add_number / d->cie_info.code_alignment); + = DW_CFA_advance_loc | exp->X_add_number; /* No more bytes needed. */ return 1; } @@ -419,23 +418,39 @@ check_eh_frame (expressionS *exp, unsigned int *pnbytes) *pnbytes = 2; } } - else if (exp->X_op == O_subtract) + else if (exp->X_op == O_subtract && d->cie_info.code_alignment == 1) { /* This is a case we can optimize. The expression was not reduced, so we can not finish the optimization until the end of the assembly. We set up a variant frag which we handle later. */ - int fr_subtype; - - if (d->cie_info.code_alignment > 0) - fr_subtype = d->cie_info.code_alignment << 3; - else - fr_subtype = 0; - - frag_var (rs_cfa, 4, 0, fr_subtype, make_expr_symbol (exp), + frag_var (rs_cfa, 4, 0, 1 << 3, make_expr_symbol (exp), d->loc4_fix, (char *) d->loc4_frag); return 1; } + else if ((exp->X_op == O_divide + || exp->X_op == O_right_shift) + && d->cie_info.code_alignment > 1) + { + if (exp->X_add_symbol->bsym + && exp->X_op_symbol->bsym + && exp->X_add_symbol->sy_value.X_op == O_subtract + && exp->X_op_symbol->sy_value.X_op == O_constant + && ((exp->X_op == O_divide + ? exp->X_op_symbol->sy_value.X_add_number + : (offsetT) 1 << exp->X_op_symbol->sy_value.X_add_number) + == (offsetT) d->cie_info.code_alignment)) + { + /* This is a case we can optimize as well. The expression was + not reduced, so we can not finish the optimization until the + end of the assembly. We set up a variant frag which we + handle later. */ + frag_var (rs_cfa, 4, 0, d->cie_info.code_alignment << 3, + make_expr_symbol (&exp->X_add_symbol->sy_value), + d->loc4_fix, (char *) d->loc4_frag); + return 1; + } + } break; case state_error: @@ -459,7 +474,9 @@ eh_frame_estimate_size_before_relax (fragS *frag) diff = resolve_symbol_value (frag->fr_symbol); - if (ca > 0 && diff % ca == 0 && diff / ca < 0x40) + assert (ca > 0); + diff /= ca; + if (diff < 0x40) ret = 0; else if (diff < 0x100) ret = 1; @@ -496,21 +513,21 @@ eh_frame_convert_frag (fragS *frag) { offsetT diff; fragS *loc4_frag; - int loc4_fix; + int loc4_fix, ca; loc4_frag = (fragS *) frag->fr_opcode; loc4_fix = (int) frag->fr_offset; diff = resolve_symbol_value (frag->fr_symbol); + ca = frag->fr_subtype >> 3; + assert (ca > 0); + diff /= ca; switch (frag->fr_subtype & 7) { case 0: - { - int ca = frag->fr_subtype >> 3; - assert (ca > 0 && diff % ca == 0 && diff / ca < 0x40); - loc4_frag->fr_literal[loc4_fix] = DW_CFA_advance_loc | (diff / ca); - } + assert (diff < 0x40); + loc4_frag->fr_literal[loc4_fix] = DW_CFA_advance_loc | diff; break; case 1: |