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| author | Peter Bergner <bergner@vnet.ibm.com> | 2011-02-02 14:08:06 -0600 |
|---|---|---|
| committer | Peter Bergner <bergner@gcc.gnu.org> | 2011-02-02 14:08:06 -0600 |
| commit | 9cd4f22a4519538f2feffa8997ac309d5dcd54b7 (patch) | |
| tree | 2a6c8c9833162d25bb4977072dccdd2ac9b0af48 /gcc/df-scan.c | |
| parent | 8e2bc95be59aa82767921fe0b83e0da93caaa611 (diff) | |
| download | gcc-9cd4f22a4519538f2feffa8997ac309d5dcd54b7.zip gcc-9cd4f22a4519538f2feffa8997ac309d5dcd54b7.tar.gz gcc-9cd4f22a4519538f2feffa8997ac309d5dcd54b7.tar.bz2 | |
re PR rtl-optimization/47525 (DCE fails to eliminate a dead call to a pure function when compiled with -maltivec)
PR rtl-optimization/47525
* df-scan.c: Update copyright years.
(df_get_call_refs): Do not mark global registers as DF_REF_REG_USE
and non-clobber DF_REF_REG_DEF for calls to const and pure functions.
From-SVN: r169768
Diffstat (limited to 'gcc/df-scan.c')
| -rw-r--r-- | gcc/df-scan.c | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/gcc/df-scan.c b/gcc/df-scan.c index 1400d25..42b4b14 100644 --- a/gcc/df-scan.c +++ b/gcc/df-scan.c @@ -1,6 +1,6 @@ /* Scanning of rtl for dataflow analysis. Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, - 2008, 2009, 2010 Free Software Foundation, Inc. + 2008, 2009, 2010, 2011 Free Software Foundation, Inc. Originally contributed by Michael P. Hayes (m.hayes@elec.canterbury.ac.nz, mhayes@redhat.com) Major rewrite contributed by Danny Berlin (dberlin@dberlin.org) @@ -3360,16 +3360,19 @@ df_get_call_refs (struct df_collection_rec * collection_rec, NULL, bb, insn_info, DF_REF_REG_USE, DF_REF_CALL_STACK_USAGE | flags); - /* Calls may also reference any of the global registers, - so they are recorded as used. */ - for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) - if (global_regs[i]) - { - df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i], - NULL, bb, insn_info, DF_REF_REG_USE, flags); - df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i], - NULL, bb, insn_info, DF_REF_REG_DEF, flags); - } + /* Calls to const functions cannot access any global registers and calls to + pure functions cannot set them. All other calls may reference any of the + global registers, so they are recorded as used. */ + if (!RTL_CONST_CALL_P (insn_info->insn)) + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) + if (global_regs[i]) + { + df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i], + NULL, bb, insn_info, DF_REF_REG_USE, flags); + if (!RTL_PURE_CALL_P (insn_info->insn)) + df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i], + NULL, bb, insn_info, DF_REF_REG_DEF, flags); + } is_sibling_call = SIBLING_CALL_P (insn_info->insn); EXECUTE_IF_SET_IN_BITMAP (regs_invalidated_by_call_regset, 0, ui, bi) |