From 5447c6eb865f760bd6ab9055a725d8eb563a6ecc Mon Sep 17 00:00:00 2001 From: jsm28 Date: Mon, 21 Nov 2005 01:19:00 +0000 Subject: [PATCH] * combine.c (try_combine): Do not run subst on i1src and i2src in the case of generating a PARALLEL for a comparison. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@107273 138bc75d-0d04-0410-961f-82ee72b054a4 --- gcc/ChangeLog | 5 +++++ gcc/combine.c | 64 ++++++++++++++++++++++++++++++++--------------------------- 2 files changed, 40 insertions(+), 29 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 765291e4ae64..bc2a54edb17f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2005-11-20 Joseph S. Myers + + * combine.c (try_combine): Do not run subst on i1src and i2src in + the case of generating a PARALLEL for a comparison. + 2005-11-20 Richard Henderson PR 24931 diff --git a/gcc/combine.c b/gcc/combine.c index b43b9b621c66..6497336bf442 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -2080,35 +2080,6 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p) subst_insn = i3; - /* It is possible that the source of I2 or I1 may be performing an - unneeded operation, such as a ZERO_EXTEND of something that is known - to have the high part zero. Handle that case by letting subst look at - the innermost one of them. - - Another way to do this would be to have a function that tries to - simplify a single insn instead of merging two or more insns. We don't - do this because of the potential of infinite loops and because - of the potential extra memory required. However, doing it the way - we are is a bit of a kludge and doesn't catch all cases. - - But only do this if -fexpensive-optimizations since it slows things down - and doesn't usually win. */ - - if (flag_expensive_optimizations) - { - /* Pass pc_rtx so no substitutions are done, just simplifications. */ - if (i1) - { - subst_low_cuid = INSN_CUID (i1); - i1src = subst (i1src, pc_rtx, pc_rtx, 0, 0); - } - else - { - subst_low_cuid = INSN_CUID (i2); - i2src = subst (i2src, pc_rtx, pc_rtx, 0, 0); - } - } - #ifndef HAVE_cc0 /* Many machines that don't use CC0 have insns that can both perform an arithmetic operation and set the condition code. These operations will @@ -2171,6 +2142,41 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p) else #endif { + /* It is possible that the source of I2 or I1 may be performing + an unneeded operation, such as a ZERO_EXTEND of something + that is known to have the high part zero. Handle that case + by letting subst look at the innermost one of them. + + Another way to do this would be to have a function that tries + to simplify a single insn instead of merging two or more + insns. We don't do this because of the potential of infinite + loops and because of the potential extra memory required. + However, doing it the way we are is a bit of a kludge and + doesn't catch all cases. + + But only do this if -fexpensive-optimizations since it slows + things down and doesn't usually win. + + This is not done in the COMPARE case above because the + unmodified I2PAT is used in the PARALLEL and so a pattern + with a modified I2SRC would not match. */ + + if (flag_expensive_optimizations) + { + /* Pass pc_rtx so no substitutions are done, just + simplifications. */ + if (i1) + { + subst_low_cuid = INSN_CUID (i1); + i1src = subst (i1src, pc_rtx, pc_rtx, 0, 0); + } + else + { + subst_low_cuid = INSN_CUID (i2); + i2src = subst (i2src, pc_rtx, pc_rtx, 0, 0); + } + } + n_occurrences = 0; /* `subst' counts here */ /* If I1 feeds into I2 (not into I3) and I1DEST is in I1SRC, we -- 2.11.4.GIT