diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ceca00fa137ded4625678f73b199bf8e6cf2496c..c1fdc2ccaca4361bf5fc750be65c6789e1e7907d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,4 +1,28 @@
-003-02-20 Aldy Hernandez <aldyh@redhat.com>
+2003-02-25 Vladimir Makarov <vmakarov@redhat.com>
+ Richard Henderson <rth@redhat.com>
+
+ * sched-int.h (INSN_TRAP_CLASS, WORST_CLASS): Move them from
+ sched-rgn.c.
+ (add_forward_dependence): New function prototype.
+
+ * sched-rgn.c (INSN_TRAP_CLASS, WORST_CLASS): Move them to
+ sched-init.h.
+ (CONST_BASED_ADDRESS_P, may_trap_exp, haifa_classify_insn): Move
+ them to haifa-sched.c.
+
+ * haifa-sched.c (CONST_BASED_ADDRESS_P, may_trap_exp,
+ haifa_classify_insn): Move them from sched-rgn.c.
+
+ * sched-deps.c (add_dependence): Return flag of creating a new
+ entry.
+ (add_forward_dependence): New function.
+ (compute_forward_dependences): Use the function.
+
+ * sched-ebb.c (earliest_block_with_similiar_load): New function.
+ (add_deps_for_risky_insns): New function.
+ (schedule_ebb): Call the function.
+
+2003-02-20 Aldy Hernandez <aldyh@redhat.com>
* doc/tm.texi: Document Rename TARGET_VECTOR_TYPES_COMPATIBLE to
TARGET_VECTOR_OPAQUE_P. Document accordingly.
diff --git a/gcc/haifa-sched.c b/gcc/haifa-sched.c
index a06c2f9307179f9fd8c17555abb50affa470dfee..8ea2481ce81693bf31e2fa64d524e9f7e3cbd485 100644
--- a/gcc/haifa-sched.c
+++ b/gcc/haifa-sched.c
@@ -305,6 +305,170 @@ struct ready_list
int n_ready;
};
+static int may_trap_exp PARAMS ((rtx, int));
+
+/* Nonzero iff the address is comprised from at most 1 register. */
+#define CONST_BASED_ADDRESS_P(x) \
+ (GET_CODE (x) == REG \
+ || ((GET_CODE (x) == PLUS || GET_CODE (x) == MINUS \
+ || (GET_CODE (x) == LO_SUM)) \
+ && (CONSTANT_P (XEXP (x, 0)) \
+ || CONSTANT_P (XEXP (x, 1)))))
+
+/* Returns a class that insn with GET_DEST(insn)=x may belong to,
+ as found by analyzing insn's expression. */
+
+static int
+may_trap_exp (x, is_store)
+ rtx x;
+ int is_store;
+{
+ enum rtx_code code;
+
+ if (x == 0)
+ return TRAP_FREE;
+ code = GET_CODE (x);
+ if (is_store)
+ {
+ if (code == MEM && may_trap_p (x))
+ return TRAP_RISKY;
+ else
+ return TRAP_FREE;
+ }
+ if (code == MEM)
+ {
+ /* The insn uses memory: a volatile load. */
+ if (MEM_VOLATILE_P (x))
+ return IRISKY;
+ /* An exception-free load. */
+ if (!may_trap_p (x))
+ return IFREE;
+ /* A load with 1 base register, to be further checked. */
+ if (CONST_BASED_ADDRESS_P (XEXP (x, 0)))
+ return PFREE_CANDIDATE;
+ /* No info on the load, to be further checked. */
+ return PRISKY_CANDIDATE;
+ }
+ else
+ {
+ const char *fmt;
+ int i, insn_class = TRAP_FREE;
+
+ /* Neither store nor load, check if it may cause a trap. */
+ if (may_trap_p (x))
+ return TRAP_RISKY;
+ /* Recursive step: walk the insn... */
+ fmt = GET_RTX_FORMAT (code);
+ for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+ {
+ if (fmt[i] == 'e')
+ {
+ int tmp_class = may_trap_exp (XEXP (x, i), is_store);
+ insn_class = WORST_CLASS (insn_class, tmp_class);
+ }
+ else if (fmt[i] == 'E')
+ {
+ int j;
+ for (j = 0; j < XVECLEN (x, i); j++)
+ {
+ int tmp_class = may_trap_exp (XVECEXP (x, i, j), is_store);
+ insn_class = WORST_CLASS (insn_class, tmp_class);
+ if (insn_class == TRAP_RISKY || insn_class == IRISKY)
+ break;
+ }
+ }
+ if (insn_class == TRAP_RISKY || insn_class == IRISKY)
+ break;
+ }
+ return insn_class;
+ }
+}
+
+/* Classifies insn for the purpose of verifying that it can be
+ moved speculatively, by examining it's patterns, returning:
+ TRAP_RISKY: store, or risky non-load insn (e.g. division by variable).
+ TRAP_FREE: non-load insn.
+ IFREE: load from a globaly safe location.
+ IRISKY: volatile load.
+ PFREE_CANDIDATE, PRISKY_CANDIDATE: load that need to be checked for
+ being either PFREE or PRISKY. */
+
+int
+haifa_classify_insn (insn)
+ rtx insn;
+{
+ rtx pat = PATTERN (insn);
+ int tmp_class = TRAP_FREE;
+ int insn_class = TRAP_FREE;
+ enum rtx_code code;
+
+ if (GET_CODE (pat) == PARALLEL)
+ {
+ int i, len = XVECLEN (pat, 0);
+
+ for (i = len - 1; i >= 0; i--)
+ {
+ code = GET_CODE (XVECEXP (pat, 0, i));
+ switch (code)
+ {
+ case CLOBBER:
+ /* Test if it is a 'store'. */
+ tmp_class = may_trap_exp (XEXP (XVECEXP (pat, 0, i), 0), 1);
+ break;
+ case SET:
+ /* Test if it is a store. */
+ tmp_class = may_trap_exp (SET_DEST (XVECEXP (pat, 0, i)), 1);
+ if (tmp_class == TRAP_RISKY)
+ break;
+ /* Test if it is a load. */
+ tmp_class
+ = WORST_CLASS (tmp_class,
+ may_trap_exp (SET_SRC (XVECEXP (pat, 0, i)),
+ 0));
+ break;
+ case COND_EXEC:
+ case TRAP_IF:
+ tmp_class = TRAP_RISKY;
+ break;
+ default:
+ ;
+ }
+ insn_class = WORST_CLASS (insn_class, tmp_class);
+ if (insn_class == TRAP_RISKY || insn_class == IRISKY)
+ break;
+ }
+ }
+ else
+ {
+ code = GET_CODE (pat);
+ switch (code)
+ {
+ case CLOBBER:
+ /* Test if it is a 'store'. */
+ tmp_class = may_trap_exp (XEXP (pat, 0), 1);
+ break;
+ case SET:
+ /* Test if it is a store. */
+ tmp_class = may_trap_exp (SET_DEST (pat), 1);
+ if (tmp_class == TRAP_RISKY)
+ break;
+ /* Test if it is a load. */
+ tmp_class =
+ WORST_CLASS (tmp_class,
+ may_trap_exp (SET_SRC (pat), 0));
+ break;
+ case COND_EXEC:
+ case TRAP_IF:
+ tmp_class = TRAP_RISKY;
+ break;
+ default:;
+ }
+ insn_class = tmp_class;
+ }
+
+ return insn_class;
+}
+
/* Forward declarations. */
/* The scheduler using only DFA description should never use the
diff --git a/gcc/sched-deps.c b/gcc/sched-deps.c
index fc9d4d857db8eac0b03c46176ca71db3b3f59fd5..b3c619df51d613172ef54144daec6040b4fb40c9 100644
--- a/gcc/sched-deps.c
+++ b/gcc/sched-deps.c
@@ -173,10 +173,11 @@ conditions_mutex_p (cond1, cond2)
}
/* Add ELEM wrapped in an INSN_LIST with reg note kind DEP_TYPE to the
- LOG_LINKS of INSN, if not already there. DEP_TYPE indicates the type
- of dependence that this link represents. */
+ LOG_LINKS of INSN, if not already there. DEP_TYPE indicates the
+ type of dependence that this link represents. The function returns
+ nonzero if a new entry has been added to insn's LOG_LINK. */
-void
+int
add_dependence (insn, elem, dep_type)
rtx insn;
rtx elem;
@@ -188,13 +189,13 @@ add_dependence (insn, elem, dep_type)
/* Don't depend an insn on itself. */
if (insn == elem)
- return;
+ return 0;
/* We can get a dependency on deleted insns due to optimizations in
the register allocation and reloading or due to splitting. Any
such dependency is useless and can be ignored. */
if (GET_CODE (elem) == NOTE)
- return;
+ return 0;
/* flow.c doesn't handle conditional lifetimes entirely correctly;
calls mess up the conditional lifetimes. */
@@ -213,7 +214,7 @@ add_dependence (insn, elem, dep_type)
/* Make sure second instruction doesn't affect condition of first
instruction if switched. */
&& !modified_in_p (cond2, insn))
- return;
+ return 0;
}
present_p = 1;
@@ -227,7 +228,7 @@ add_dependence (insn, elem, dep_type)
elem is a CALL is still required. */
if (GET_CODE (insn) == CALL_INSN
&& (INSN_BB (elem) != INSN_BB (insn)))
- return;
+ return 0;
#endif
/* If we already have a dependency for ELEM, then we do not need to
@@ -251,7 +252,7 @@ add_dependence (insn, elem, dep_type)
else
present_p = 0;
if (present_p && (int) dep_type >= (int) present_dep_type)
- return;
+ return 0;
}
#endif
@@ -276,7 +277,7 @@ add_dependence (insn, elem, dep_type)
abort ();
}
#endif
-
+
/* If this is a more restrictive type of dependence than the existing
one, then change the existing dependence to this type. */
if ((int) dep_type < (int) REG_NOTE_KIND (link))
@@ -298,8 +299,8 @@ add_dependence (insn, elem, dep_type)
INSN_LUID (elem));
}
#endif
- return;
- }
+ return 0;
+ }
/* Might want to check one level of transitivity to save conses. */
link = alloc_INSN_LIST (elem, LOG_LINKS (insn));
@@ -321,6 +322,7 @@ add_dependence (insn, elem, dep_type)
SET_BIT (output_dependency_cache[INSN_LUID (insn)], INSN_LUID (elem));
}
#endif
+ return 1;
}
/* A convenience wrapper to operate on an entire list. */
@@ -1310,6 +1312,46 @@ sched_analyze (deps, head, tail)
abort ();
}
+
+/* The following function adds forward dependence (FROM, TO) with
+ given DEP_TYPE. The forward dependence should be not exist before. */
+
+void
+add_forward_dependence (from, to, dep_type)
+ rtx from;
+ rtx to;
+ enum reg_note dep_type;
+{
+ rtx new_link;
+
+#ifdef ENABLE_CHECKING
+ /* If add_dependence is working properly there should never
+ be notes, deleted insns or duplicates in the backward
+ links. Thus we need not check for them here.
+
+ However, if we have enabled checking we might as well go
+ ahead and verify that add_dependence worked properly. */
+ if (GET_CODE (from) == NOTE
+ || INSN_DELETED_P (from)
+ || (forward_dependency_cache != NULL
+ && TEST_BIT (forward_dependency_cache[INSN_LUID (from)],
+ INSN_LUID (to)))
+ || (forward_dependency_cache == NULL
+ && find_insn_list (to, INSN_DEPEND (from))))
+ abort ();
+ if (forward_dependency_cache != NULL)
+ SET_BIT (forward_dependency_cache[INSN_LUID (from)],
+ INSN_LUID (to));
+#endif
+
+ new_link = alloc_INSN_LIST (to, INSN_DEPEND (from));
+
+ PUT_REG_NOTE_KIND (new_link, dep_type);
+
+ INSN_DEPEND (from) = new_link;
+ INSN_DEP_COUNT (to) += 1;
+}
+
/* Examine insns in the range [ HEAD, TAIL ] and Use the backward
dependences from LOG_LINKS to build forward dependences in
INSN_DEPEND. */
@@ -1320,7 +1362,6 @@ compute_forward_dependences (head, tail)
{
rtx insn, link;
rtx next_tail;
- enum reg_note dep_type;
next_tail = NEXT_INSN (tail);
for (insn = head; insn != next_tail; insn = NEXT_INSN (insn))
@@ -1329,41 +1370,7 @@ compute_forward_dependences (head, tail)
continue;
for (link = LOG_LINKS (insn); link; link = XEXP (link, 1))
- {
- rtx x = XEXP (link, 0);
- rtx new_link;
-
- if (x != XEXP (link, 0))
- continue;
-
-#ifdef ENABLE_CHECKING
- /* If add_dependence is working properly there should never
- be notes, deleted insns or duplicates in the backward
- links. Thus we need not check for them here.
-
- However, if we have enabled checking we might as well go
- ahead and verify that add_dependence worked properly. */
- if (GET_CODE (x) == NOTE
- || INSN_DELETED_P (x)
- || (forward_dependency_cache != NULL
- && TEST_BIT (forward_dependency_cache[INSN_LUID (x)],
- INSN_LUID (insn)))
- || (forward_dependency_cache == NULL
- && find_insn_list (insn, INSN_DEPEND (x))))
- abort ();
- if (forward_dependency_cache != NULL)
- SET_BIT (forward_dependency_cache[INSN_LUID (x)],
- INSN_LUID (insn));
-#endif
-
- new_link = alloc_INSN_LIST (insn, INSN_DEPEND (x));
-
- dep_type = REG_NOTE_KIND (link);
- PUT_REG_NOTE_KIND (new_link, dep_type);
-
- INSN_DEPEND (x) = new_link;
- INSN_DEP_COUNT (insn) += 1;
- }
+ add_forward_dependence (XEXP (link, 0), insn, REG_NOTE_KIND (link));
}
}
diff --git a/gcc/sched-ebb.c b/gcc/sched-ebb.c
index eefee1c168a97cef68ca0fad4bccc67e7ada1da5..3d25d80da374130e821702602af1accb580b71d5 100644
--- a/gcc/sched-ebb.c
+++ b/gcc/sched-ebb.c
@@ -56,6 +56,9 @@ static const char *ebb_print_insn PARAMS ((rtx, int));
static int rank PARAMS ((rtx, rtx));
static int contributes_to_priority PARAMS ((rtx, rtx));
static void compute_jump_reg_dependencies PARAMS ((rtx, regset));
+static basic_block earliest_block_with_similiar_load PARAMS ((basic_block,
+ rtx));
+static void add_deps_for_risky_insns PARAMS ((rtx, rtx));
static basic_block schedule_ebb PARAMS ((rtx, rtx));
static basic_block fix_basic_block_boundaries PARAMS ((basic_block, basic_block, rtx, rtx));
static void add_missing_bbs PARAMS ((rtx, basic_block, basic_block));
@@ -339,6 +342,137 @@ fix_basic_block_boundaries (bb, last, head, tail)
return bb->prev_bb;
}
+/* Returns the earliest block in EBB currently being processed where a
+ "similar load" 'insn2' is found, and hence LOAD_INSN can move
+ speculatively into the found block. All the following must hold:
+
+ (1) both loads have 1 base register (PFREE_CANDIDATEs).
+ (2) load_insn and load2 have a def-use dependence upon
+ the same insn 'insn1'.
+
+ From all these we can conclude that the two loads access memory
+ addresses that differ at most by a constant, and hence if moving
+ load_insn would cause an exception, it would have been caused by
+ load2 anyhow.
+
+ The function uses list (given by LAST_BLOCK) of already processed
+ blocks in EBB. The list is formed in `add_deps_for_risky_insns'. */
+
+static basic_block
+earliest_block_with_similiar_load (last_block, load_insn)
+ basic_block last_block;
+ rtx load_insn;
+{
+ rtx back_link;
+ basic_block bb, earliest_block = NULL;
+
+ for (back_link = LOG_LINKS (load_insn);
+ back_link;
+ back_link = XEXP (back_link, 1))
+ {
+ rtx insn1 = XEXP (back_link, 0);
+
+ if (GET_MODE (back_link) == VOIDmode)
+ {
+ /* Found a DEF-USE dependence (insn1, load_insn). */
+ rtx fore_link;
+
+ for (fore_link = INSN_DEPEND (insn1);
+ fore_link;
+ fore_link = XEXP (fore_link, 1))
+ {
+ rtx insn2 = XEXP (fore_link, 0);
+ basic_block insn2_block = BLOCK_FOR_INSN (insn2);
+
+ if (GET_MODE (fore_link) == VOIDmode)
+ {
+ if (earliest_block != NULL
+ && earliest_block->index < insn2_block->index)
+ continue;
+
+ /* Found a DEF-USE dependence (insn1, insn2). */
+ if (haifa_classify_insn (insn2) != PFREE_CANDIDATE)
+ /* insn2 not guaranteed to be a 1 base reg load. */
+ continue;
+
+ for (bb = last_block; bb; bb = bb->aux)
+ if (insn2_block == bb)
+ break;
+
+ if (!bb)
+ /* insn2 is the similar load. */
+ earliest_block = insn2_block;
+ }
+ }
+ }
+ }
+
+ return earliest_block;
+}
+
+/* The following function adds dependecies between jumps and risky
+ insns in given ebb. */
+
+static void
+add_deps_for_risky_insns (head, tail)
+ rtx head, tail;
+{
+ rtx insn, prev;
+ int class;
+ rtx last_jump = NULL_RTX;
+ rtx next_tail = NEXT_INSN (tail);
+ basic_block last_block = NULL, bb;
+
+ for (insn = head; insn != next_tail; insn = NEXT_INSN (insn))
+ if (GET_CODE (insn) == JUMP_INSN)
+ {
+ bb = BLOCK_FOR_INSN (insn);
+ bb->aux = last_block;
+ last_block = bb;
+ last_jump = insn;
+ }
+ else if (INSN_P (insn) && last_jump != NULL_RTX)
+ {
+ class = haifa_classify_insn (insn);
+ prev = last_jump;
+ switch (class)
+ {
+ case PFREE_CANDIDATE:
+ if (flag_schedule_speculative_load)
+ {
+ bb = earliest_block_with_similiar_load (last_block, insn);
+ if (bb)
+ bb = bb->aux;
+ if (!bb)
+ break;
+ prev = bb->end;
+ }
+ /* FALLTHRU */
+ case TRAP_RISKY:
+ case IRISKY:
+ case PRISKY_CANDIDATE:
+ /* ??? We could implement better checking PRISKY_CANDIATEs
+ analogous to sched-rgn.c. */
+ /* We can not change the mode of the backward
+ dependency because REG_DEP_ANTI has the lowest
+ rank. */
+ if (add_dependence (insn, prev, REG_DEP_ANTI))
+ add_forward_dependence (prev, insn, REG_DEP_ANTI);
+ break;
+
+ default:
+ break;
+ }
+ }
+ /* Maintain the invariant that bb->aux is clear after use. */
+ while (last_block)
+ {
+ bb = last_block->aux;
+ last_block->aux = NULL;
+ last_block = bb;
+ }
+}
+
/* Schedule a single extended basic block, defined by the boundaries HEAD
and TAIL. */
@@ -365,6 +499,8 @@ schedule_ebb (head, tail)
/* Compute INSN_DEPEND. */
compute_forward_dependences (head, tail);
+ add_deps_for_risky_insns (head, tail);
+
if (targetm.sched.dependencies_evaluation_hook)
targetm.sched.dependencies_evaluation_hook (head, tail);
diff --git a/gcc/sched-int.h b/gcc/sched-int.h
index 1b196562b184f772c0db6e5dad5943b2ba883451..2041a2f5e3910dbf50544a6a93cc5d1b93bb2140 100644
--- a/gcc/sched-int.h
+++ b/gcc/sched-int.h
@@ -258,6 +258,76 @@ extern struct haifa_insn_data *h_i_d;
extern FILE *sched_dump;
extern int sched_verbose;
+/* Exception Free Loads:
+
+ We define five classes of speculative loads: IFREE, IRISKY,
+ PFREE, PRISKY, and MFREE.
+
+ IFREE loads are loads that are proved to be exception-free, just
+ by examining the load insn. Examples for such loads are loads
+ from TOC and loads of global data.
+
+ IRISKY loads are loads that are proved to be exception-risky,
+ just by examining the load insn. Examples for such loads are
+ volatile loads and loads from shared memory.
+
+ PFREE loads are loads for which we can prove, by examining other
+ insns, that they are exception-free. Currently, this class consists
+ of loads for which we are able to find a "similar load", either in
+ the target block, or, if only one split-block exists, in that split
+ block. Load2 is similar to load1 if both have same single base
+ register. We identify only part of the similar loads, by finding
+ an insn upon which both load1 and load2 have a DEF-USE dependence.
+
+ PRISKY loads are loads for which we can prove, by examining other
+ insns, that they are exception-risky. Currently we have two proofs for
+ such loads. The first proof detects loads that are probably guarded by a
+ test on the memory address. This proof is based on the
+ backward and forward data dependence information for the region.
+ Let load-insn be the examined load.
+ Load-insn is PRISKY iff ALL the following hold:
+
+ - insn1 is not in the same block as load-insn
+ - there is a DEF-USE dependence chain (insn1, ..., load-insn)
+ - test-insn is either a compare or a branch, not in the same block
+ as load-insn
+ - load-insn is reachable from test-insn
+ - there is a DEF-USE dependence chain (insn1, ..., test-insn)
+
+ This proof might fail when the compare and the load are fed
+ by an insn not in the region. To solve this, we will add to this
+ group all loads that have no input DEF-USE dependence.
+
+ The second proof detects loads that are directly or indirectly
+ fed by a speculative load. This proof is affected by the
+ scheduling process. We will use the flag fed_by_spec_load.
+ Initially, all insns have this flag reset. After a speculative
+ motion of an insn, if insn is either a load, or marked as
+ fed_by_spec_load, we will also mark as fed_by_spec_load every
+ insn1 for which a DEF-USE dependence (insn, insn1) exists. A
+ load which is fed_by_spec_load is also PRISKY.
+
+ MFREE (maybe-free) loads are all the remaining loads. They may be
+ exception-free, but we cannot prove it.
+
+ Now, all loads in IFREE and PFREE classes are considered
+ exception-free, while all loads in IRISKY and PRISKY classes are
+ considered exception-risky. As for loads in the MFREE class,
+ these are considered either exception-free or exception-risky,
+ depending on whether we are pessimistic or optimistic. We have
+ to take the pessimistic approach to assure the safety of
+ speculative scheduling, but we can take the optimistic approach
+ by invoking the -fsched_spec_load_dangerous option. */
+
+enum INSN_TRAP_CLASS
+{
+ TRAP_FREE = 0, IFREE = 1, PFREE_CANDIDATE = 2,
+ PRISKY_CANDIDATE = 3, IRISKY = 4, TRAP_RISKY = 5
+};
+
+#define WORST_CLASS(class1, class2) \
+((class1 > class2) ? class1 : class2)
+
#ifndef __GNUC__
#define __inline
#endif
@@ -278,7 +348,7 @@ extern void visualize_alloc PARAMS ((void));
extern void visualize_free PARAMS ((void));
/* Functions in sched-deps.c. */
-extern void add_dependence PARAMS ((rtx, rtx, enum reg_note));
+extern int add_dependence PARAMS ((rtx, rtx, enum reg_note));
extern void add_insn_mem_dependence PARAMS ((struct deps *, rtx *, rtx *, rtx,
rtx));
extern void sched_analyze PARAMS ((struct deps *, rtx, rtx));
@@ -286,12 +356,14 @@ extern void init_deps PARAMS ((struct deps *));
extern void free_deps PARAMS ((struct deps *));
extern void init_deps_global PARAMS ((void));
extern void finish_deps_global PARAMS ((void));
+extern void add_forward_dependence PARAMS ((rtx, rtx, enum reg_note));
extern void compute_forward_dependences PARAMS ((rtx, rtx));
extern rtx find_insn_list PARAMS ((rtx, rtx));
extern void init_dependency_caches PARAMS ((int));
extern void free_dependency_caches PARAMS ((void));
/* Functions in haifa-sched.c. */
+extern int haifa_classify_insn PARAMS ((rtx));
extern void get_block_head_tail PARAMS ((int, rtx *, rtx *));
extern int no_real_insns_p PARAMS ((rtx, rtx));
diff --git a/gcc/sched-rgn.c b/gcc/sched-rgn.c
index 36a53f73c26162bc35f7f299dcfb5395b59791ba..c7e7f808ee93f284885e02aa152118000fb39016 100644
--- a/gcc/sched-rgn.c
+++ b/gcc/sched-rgn.c
@@ -288,8 +288,6 @@ static void set_spec_fed PARAMS ((rtx));
static int is_pfree PARAMS ((rtx, int, int));
static int find_conditional_protection PARAMS ((rtx, int));
static int is_conditionally_protected PARAMS ((rtx, int, int));
-static int may_trap_exp PARAMS ((rtx, int));
-static int haifa_classify_insn PARAMS ((rtx));
static int is_prisky PARAMS ((rtx, int, int));
static int is_exception_free PARAMS ((rtx, int, int));
@@ -1490,76 +1488,6 @@ update_live (insn, src)
}
}
-/* Exception Free Loads:
-
- We define five classes of speculative loads: IFREE, IRISKY,
- PFREE, PRISKY, and MFREE.
-
- IFREE loads are loads that are proved to be exception-free, just
- by examining the load insn. Examples for such loads are loads
- from TOC and loads of global data.
-
- IRISKY loads are loads that are proved to be exception-risky,
- just by examining the load insn. Examples for such loads are
- volatile loads and loads from shared memory.
-
- PFREE loads are loads for which we can prove, by examining other
- insns, that they are exception-free. Currently, this class consists
- of loads for which we are able to find a "similar load", either in
- the target block, or, if only one split-block exists, in that split
- block. Load2 is similar to load1 if both have same single base
- register. We identify only part of the similar loads, by finding
- an insn upon which both load1 and load2 have a DEF-USE dependence.
-
- PRISKY loads are loads for which we can prove, by examining other
- insns, that they are exception-risky. Currently we have two proofs for
- such loads. The first proof detects loads that are probably guarded by a
- test on the memory address. This proof is based on the
- backward and forward data dependence information for the region.
- Let load-insn be the examined load.
- Load-insn is PRISKY iff ALL the following hold:
-
- - insn1 is not in the same block as load-insn
- - there is a DEF-USE dependence chain (insn1, ..., load-insn)
- - test-insn is either a compare or a branch, not in the same block
- as load-insn
- - load-insn is reachable from test-insn
- - there is a DEF-USE dependence chain (insn1, ..., test-insn)
-
- This proof might fail when the compare and the load are fed
- by an insn not in the region. To solve this, we will add to this
- group all loads that have no input DEF-USE dependence.
-
- The second proof detects loads that are directly or indirectly
- fed by a speculative load. This proof is affected by the
- scheduling process. We will use the flag fed_by_spec_load.
- Initially, all insns have this flag reset. After a speculative
- motion of an insn, if insn is either a load, or marked as
- fed_by_spec_load, we will also mark as fed_by_spec_load every
- insn1 for which a DEF-USE dependence (insn, insn1) exists. A
- load which is fed_by_spec_load is also PRISKY.
-
- MFREE (maybe-free) loads are all the remaining loads. They may be
- exception-free, but we cannot prove it.
-
- Now, all loads in IFREE and PFREE classes are considered
- exception-free, while all loads in IRISKY and PRISKY classes are
- considered exception-risky. As for loads in the MFREE class,
- these are considered either exception-free or exception-risky,
- depending on whether we are pessimistic or optimistic. We have
- to take the pessimistic approach to assure the safety of
- speculative scheduling, but we can take the optimistic approach
- by invoking the -fsched_spec_load_dangerous option. */
-
-enum INSN_TRAP_CLASS
-{
- TRAP_FREE = 0, IFREE = 1, PFREE_CANDIDATE = 2,
- PRISKY_CANDIDATE = 3, IRISKY = 4, TRAP_RISKY = 5
-};
-
-#define WORST_CLASS(class1, class2) \
-((class1 > class2) ? class1 : class2)
-
/* Nonzero if block bb_to is equal to, or reachable from block bb_from. */
#define IS_REACHABLE(bb_from, bb_to) \
(bb_from == bb_to \
@@ -1567,14 +1495,6 @@ enum INSN_TRAP_CLASS
|| (TEST_BIT (ancestor_edges[bb_to], \
EDGE_TO_BIT (IN_EDGES (BB_TO_BLOCK (bb_from))))))
-/* Nonzero iff the address is comprised from at most 1 register. */
-#define CONST_BASED_ADDRESS_P(x) \
- (GET_CODE (x) == REG \
- || ((GET_CODE (x) == PLUS || GET_CODE (x) == MINUS \
- || (GET_CODE (x) == LO_SUM)) \
- && (CONSTANT_P (XEXP (x, 0)) \
- || CONSTANT_P (XEXP (x, 1)))))
-
/* Turns on the fed_by_spec_load flag for insns fed by load_insn. */
static void
@@ -1729,160 +1649,6 @@ is_pfree (load_insn, bb_src, bb_trg)
return 0;
} /* is_pfree */
-/* Returns a class that insn with GET_DEST(insn)=x may belong to,
- as found by analyzing insn's expression. */
-
-static int
-may_trap_exp (x, is_store)
- rtx x;
- int is_store;
-{
- enum rtx_code code;
-
- if (x == 0)
- return TRAP_FREE;
- code = GET_CODE (x);
- if (is_store)
- {
- if (code == MEM && may_trap_p (x))
- return TRAP_RISKY;
- else
- return TRAP_FREE;
- }
- if (code == MEM)
- {
- /* The insn uses memory: a volatile load. */
- if (MEM_VOLATILE_P (x))
- return IRISKY;
- /* An exception-free load. */
- if (!may_trap_p (x))
- return IFREE;
- /* A load with 1 base register, to be further checked. */
- if (CONST_BASED_ADDRESS_P (XEXP (x, 0)))
- return PFREE_CANDIDATE;
- /* No info on the load, to be further checked. */
- return PRISKY_CANDIDATE;
- }
- else
- {
- const char *fmt;
- int i, insn_class = TRAP_FREE;
-
- /* Neither store nor load, check if it may cause a trap. */
- if (may_trap_p (x))
- return TRAP_RISKY;
- /* Recursive step: walk the insn... */
- fmt = GET_RTX_FORMAT (code);
- for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
- {
- if (fmt[i] == 'e')
- {
- int tmp_class = may_trap_exp (XEXP (x, i), is_store);
- insn_class = WORST_CLASS (insn_class, tmp_class);
- }
- else if (fmt[i] == 'E')
- {
- int j;
- for (j = 0; j < XVECLEN (x, i); j++)
- {
- int tmp_class = may_trap_exp (XVECEXP (x, i, j), is_store);
- insn_class = WORST_CLASS (insn_class, tmp_class);
- if (insn_class == TRAP_RISKY || insn_class == IRISKY)
- break;
- }
- }
- if (insn_class == TRAP_RISKY || insn_class == IRISKY)
- break;
- }
- return insn_class;
- }
-}
-
-/* Classifies insn for the purpose of verifying that it can be
- moved speculatively, by examining it's patterns, returning:
- TRAP_RISKY: store, or risky non-load insn (e.g. division by variable).
- TRAP_FREE: non-load insn.
- IFREE: load from a globaly safe location.
- IRISKY: volatile load.
- PFREE_CANDIDATE, PRISKY_CANDIDATE: load that need to be checked for
- being either PFREE or PRISKY. */
-
-static int
-haifa_classify_insn (insn)
- rtx insn;
-{
- rtx pat = PATTERN (insn);
- int tmp_class = TRAP_FREE;
- int insn_class = TRAP_FREE;
- enum rtx_code code;
-
- if (GET_CODE (pat) == PARALLEL)
- {
- int i, len = XVECLEN (pat, 0);
-
- for (i = len - 1; i >= 0; i--)
- {
- code = GET_CODE (XVECEXP (pat, 0, i));
- switch (code)
- {
- case CLOBBER:
- /* Test if it is a 'store'. */
- tmp_class = may_trap_exp (XEXP (XVECEXP (pat, 0, i), 0), 1);
- break;
- case SET:
- /* Test if it is a store. */
- tmp_class = may_trap_exp (SET_DEST (XVECEXP (pat, 0, i)), 1);
- if (tmp_class == TRAP_RISKY)
- break;
- /* Test if it is a load. */
- tmp_class
- = WORST_CLASS (tmp_class,
- may_trap_exp (SET_SRC (XVECEXP (pat, 0, i)),
- 0));
- break;
- case COND_EXEC:
- case TRAP_IF:
- tmp_class = TRAP_RISKY;
- break;
- default:
- ;
- }
- insn_class = WORST_CLASS (insn_class, tmp_class);
- if (insn_class == TRAP_RISKY || insn_class == IRISKY)
- break;
- }
- }
- else
- {
- code = GET_CODE (pat);
- switch (code)
- {
- case CLOBBER:
- /* Test if it is a 'store'. */
- tmp_class = may_trap_exp (XEXP (pat, 0), 1);
- break;
- case SET:
- /* Test if it is a store. */
- tmp_class = may_trap_exp (SET_DEST (pat), 1);
- if (tmp_class == TRAP_RISKY)
- break;
- /* Test if it is a load. */
- tmp_class =
- WORST_CLASS (tmp_class,
- may_trap_exp (SET_SRC (pat), 0));
- break;
- case COND_EXEC:
- case TRAP_IF:
- tmp_class = TRAP_RISKY;
- break;
- default:;
- }
- insn_class = tmp_class;
- }
-
- return insn_class;
-}
-
/* Return 1 if load_insn is prisky (i.e. if load_insn is fed by
a load moved speculatively, or if load_insn is protected by
a compare on load_insn's address). */