From f5c4a9440f15ccf6775659910a2014a5494ee86e Mon Sep 17 00:00:00 2001 From: ebotcazou Date: Wed, 22 Nov 2017 21:43:22 +0000 Subject: [PATCH] PR rtl-optimization/83030 * doc/rtl.texi (Flags in an RTL Expression): Alphabetize, add entry for CROSSING_JUMP_P and mention usage of 'jump' for JUMP_INSNs. (Insns): Delete entry for REG_CROSSING_JUMP in register notes. * bb-reorder.c (update_crossing_jump_flags): Do not test whether the CROSSING_JUMP_P flag is already set before setting it. * cfgrtl.c (fixup_partition_crossing): Likewise. * reorg.c (relax_delay_slots): Do not consider a CROSSING_JUMP_P insn as useless. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@255083 138bc75d-0d04-0410-961f-82ee72b054a4 Upstream-Status: Backport This patch removes changes to Changelog from the original upstream patch. This will help us avoid conflicts. Original backport to GCC 7.x by Amruta Pawar Signed-off-by: Mark Hatle --- gcc/bb-reorder.c | 5 +-- gcc/cfgrtl.c | 3 +- gcc/doc/rtl.texi | 129 ++++++++++++++++++++++++++++--------------------------- gcc/reorg.c | 7 +-- 5 files changed, 84 insertions(+), 72 deletions(-) diff --git a/gcc/bb-reorder.c b/gcc/bb-reorder.c index 55e6dc6..794283c 100644 --- a/gcc/bb-reorder.c +++ b/gcc/bb-reorder.c @@ -2236,10 +2236,7 @@ update_crossing_jump_flags (void) FOR_EACH_EDGE (e, ei, bb->succs) if (e->flags & EDGE_CROSSING) { - if (JUMP_P (BB_END (bb)) - /* Some flags were added during fix_up_fall_thru_edges, via - force_nonfallthru_and_redirect. */ - && !CROSSING_JUMP_P (BB_END (bb))) + if (JUMP_P (BB_END (bb))) CROSSING_JUMP_P (BB_END (bb)) = 1; break; } diff --git a/gcc/cfgrtl.c b/gcc/cfgrtl.c index d6e5ac0..a2ad075 100644 --- a/gcc/cfgrtl.c +++ b/gcc/cfgrtl.c @@ -1334,8 +1334,7 @@ fixup_partition_crossing (edge e) if (BB_PARTITION (e->src) != BB_PARTITION (e->dest)) { e->flags |= EDGE_CROSSING; - if (JUMP_P (BB_END (e->src)) - && !CROSSING_JUMP_P (BB_END (e->src))) + if (JUMP_P (BB_END (e->src))) CROSSING_JUMP_P (BB_END (e->src)) = 1; } else if (BB_PARTITION (e->src) == BB_PARTITION (e->dest)) diff --git a/gcc/doc/rtl.texi b/gcc/doc/rtl.texi index 21524f5..a58eedc 100644 --- a/gcc/doc/rtl.texi +++ b/gcc/doc/rtl.texi @@ -565,6 +565,16 @@ that are used in certain types of expression. Most often they are accessed with the following macros, which expand into lvalues. @table @code +@findex CROSSING_JUMP_P +@cindex @code{jump_insn} and @samp{/j} +@item CROSSING_JUMP_P (@var{x}) +Nonzero in a @code{jump_insn} if it crosses between hot and cold sections, +which could potentially be very far apart in the executable. The presence +of this flag indicates to other optimizations that this branching instruction +should not be ``collapsed'' into a simpler branching construct. It is used +when the optimization to partition basic blocks into hot and cold sections +is turned on. + @findex CONSTANT_POOL_ADDRESS_P @cindex @code{symbol_ref} and @samp{/u} @cindex @code{unchanging}, in @code{symbol_ref} @@ -577,37 +587,6 @@ In either case GCC assumes these addresses can be addressed directly, perhaps with the help of base registers. Stored in the @code{unchanging} field and printed as @samp{/u}. -@findex RTL_CONST_CALL_P -@cindex @code{call_insn} and @samp{/u} -@cindex @code{unchanging}, in @code{call_insn} -@item RTL_CONST_CALL_P (@var{x}) -In a @code{call_insn} indicates that the insn represents a call to a -const function. Stored in the @code{unchanging} field and printed as -@samp{/u}. - -@findex RTL_PURE_CALL_P -@cindex @code{call_insn} and @samp{/i} -@cindex @code{return_val}, in @code{call_insn} -@item RTL_PURE_CALL_P (@var{x}) -In a @code{call_insn} indicates that the insn represents a call to a -pure function. Stored in the @code{return_val} field and printed as -@samp{/i}. - -@findex RTL_CONST_OR_PURE_CALL_P -@cindex @code{call_insn} and @samp{/u} or @samp{/i} -@item RTL_CONST_OR_PURE_CALL_P (@var{x}) -In a @code{call_insn}, true if @code{RTL_CONST_CALL_P} or -@code{RTL_PURE_CALL_P} is true. - -@findex RTL_LOOPING_CONST_OR_PURE_CALL_P -@cindex @code{call_insn} and @samp{/c} -@cindex @code{call}, in @code{call_insn} -@item RTL_LOOPING_CONST_OR_PURE_CALL_P (@var{x}) -In a @code{call_insn} indicates that the insn represents a possibly -infinite looping call to a const or pure function. Stored in the -@code{call} field and printed as @samp{/c}. Only true if one of -@code{RTL_CONST_CALL_P} or @code{RTL_PURE_CALL_P} is true. - @findex INSN_ANNULLED_BRANCH_P @cindex @code{jump_insn} and @samp{/u} @cindex @code{call_insn} and @samp{/u} @@ -702,6 +681,29 @@ Stored in the @code{call} field and printed as @samp{/c}. Nonzero in a @code{mem} if the memory reference holds a pointer. Stored in the @code{frame_related} field and printed as @samp{/f}. +@findex MEM_READONLY_P +@cindex @code{mem} and @samp{/u} +@cindex @code{unchanging}, in @code{mem} +@item MEM_READONLY_P (@var{x}) +Nonzero in a @code{mem}, if the memory is statically allocated and read-only. + +Read-only in this context means never modified during the lifetime of the +program, not necessarily in ROM or in write-disabled pages. A common +example of the later is a shared library's global offset table. This +table is initialized by the runtime loader, so the memory is technically +writable, but after control is transferred from the runtime loader to the +application, this memory will never be subsequently modified. + +Stored in the @code{unchanging} field and printed as @samp{/u}. + +@findex PREFETCH_SCHEDULE_BARRIER_P +@cindex @code{prefetch} and @samp{/v} +@cindex @code{volatile}, in @code{prefetch} +@item PREFETCH_SCHEDULE_BARRIER_P (@var{x}) +In a @code{prefetch}, indicates that the prefetch is a scheduling barrier. +No other INSNs will be moved over it. +Stored in the @code{volatil} field and printed as @samp{/v}. + @findex REG_FUNCTION_VALUE_P @cindex @code{reg} and @samp{/i} @cindex @code{return_val}, in @code{reg} @@ -731,6 +733,37 @@ The same hard register may be used also for collecting the values of functions called by this one, but @code{REG_FUNCTION_VALUE_P} is zero in this kind of use. +@findex RTL_CONST_CALL_P +@cindex @code{call_insn} and @samp{/u} +@cindex @code{unchanging}, in @code{call_insn} +@item RTL_CONST_CALL_P (@var{x}) +In a @code{call_insn} indicates that the insn represents a call to a +const function. Stored in the @code{unchanging} field and printed as +@samp{/u}. + +@findex RTL_PURE_CALL_P +@cindex @code{call_insn} and @samp{/i} +@cindex @code{return_val}, in @code{call_insn} +@item RTL_PURE_CALL_P (@var{x}) +In a @code{call_insn} indicates that the insn represents a call to a +pure function. Stored in the @code{return_val} field and printed as +@samp{/i}. + +@findex RTL_CONST_OR_PURE_CALL_P +@cindex @code{call_insn} and @samp{/u} or @samp{/i} +@item RTL_CONST_OR_PURE_CALL_P (@var{x}) +In a @code{call_insn}, true if @code{RTL_CONST_CALL_P} or +@code{RTL_PURE_CALL_P} is true. + +@findex RTL_LOOPING_CONST_OR_PURE_CALL_P +@cindex @code{call_insn} and @samp{/c} +@cindex @code{call}, in @code{call_insn} +@item RTL_LOOPING_CONST_OR_PURE_CALL_P (@var{x}) +In a @code{call_insn} indicates that the insn represents a possibly +infinite looping call to a const or pure function. Stored in the +@code{call} field and printed as @samp{/c}. Only true if one of +@code{RTL_CONST_CALL_P} or @code{RTL_PURE_CALL_P} is true. + @findex RTX_FRAME_RELATED_P @cindex @code{insn} and @samp{/f} @cindex @code{call_insn} and @samp{/f} @@ -765,21 +798,6 @@ computation performed by this instruction, i.e., one that This flag is required for exception handling support on targets with RTL prologues. -@findex MEM_READONLY_P -@cindex @code{mem} and @samp{/u} -@cindex @code{unchanging}, in @code{mem} -@item MEM_READONLY_P (@var{x}) -Nonzero in a @code{mem}, if the memory is statically allocated and read-only. - -Read-only in this context means never modified during the lifetime of the -program, not necessarily in ROM or in write-disabled pages. A common -example of the later is a shared library's global offset table. This -table is initialized by the runtime loader, so the memory is technically -writable, but after control is transferred from the runtime loader to the -application, this memory will never be subsequently modified. - -Stored in the @code{unchanging} field and printed as @samp{/u}. - @findex SCHED_GROUP_P @cindex @code{insn} and @samp{/s} @cindex @code{call_insn} and @samp{/s} @@ -879,14 +897,6 @@ Stored in the @code{volatil} field and printed as @samp{/v}. Most uses of @code{SYMBOL_REF_FLAG} are historic and may be subsumed by @code{SYMBOL_REF_FLAGS}. Certainly use of @code{SYMBOL_REF_FLAGS} is mandatory if the target requires more than one bit of storage. - -@findex PREFETCH_SCHEDULE_BARRIER_P -@cindex @code{prefetch} and @samp{/v} -@cindex @code{volatile}, in @code{prefetch} -@item PREFETCH_SCHEDULE_BARRIER_P (@var{x}) -In a @code{prefetch}, indicates that the prefetch is a scheduling barrier. -No other INSNs will be moved over it. -Stored in the @code{volatil} field and printed as @samp{/v}. @end table These are the fields to which the above macros refer: @@ -974,6 +985,8 @@ In a @code{set}, 1 means it is for a return. In a @code{call_insn}, 1 means it is a sibling call. +In a @code{jump_insn}, 1 means it is a crossing jump. + In an RTL dump, this flag is represented as @samp{/j}. @findex unchanging @@ -3887,16 +3900,6 @@ multiple targets; the last label in the insn (in the highest numbered insn-field) goes into the @code{JUMP_LABEL} field and does not have a @code{REG_LABEL_TARGET} note. @xref{Insns, JUMP_LABEL}. -@findex REG_CROSSING_JUMP -@item REG_CROSSING_JUMP -This insn is a branching instruction (either an unconditional jump or -an indirect jump) which crosses between hot and cold sections, which -could potentially be very far apart in the executable. The presence -of this note indicates to other optimizations that this branching -instruction should not be ``collapsed'' into a simpler branching -construct. It is used when the optimization to partition basic blocks -into hot and cold sections is turned on. - @findex REG_SETJMP @item REG_SETJMP Appears attached to each @code{CALL_INSN} to @code{setjmp} or a diff --git a/gcc/reorg.c b/gcc/reorg.c index 5914af6..77f3fe7 100644 --- a/gcc/reorg.c +++ b/gcc/reorg.c @@ -3360,10 +3360,11 @@ relax_delay_slots (rtx_insn *first) } /* See if we have a simple (conditional) jump that is useless. */ - if (! INSN_ANNULLED_BRANCH_P (delay_jump_insn) - && ! condjump_in_parallel_p (delay_jump_insn) + if (!CROSSING_JUMP_P (delay_jump_insn) + && !INSN_ANNULLED_BRANCH_P (delay_jump_insn) + && !condjump_in_parallel_p (delay_jump_insn) && prev_active_insn (as_a (target_label)) == insn - && ! BARRIER_P (prev_nonnote_insn (as_a (target_label))) + && !BARRIER_P (prev_nonnote_insn (as_a (target_label))) /* If the last insn in the delay slot sets CC0 for some insn, various code assumes that it is in a delay slot. We could put it back where it belonged and delete the register notes, -- 1.8.5.6