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authorRichard Sandiford <rdsandiford@googlemail.com>2010-07-12 19:03:25 +0000
committerRichard Sandiford <rsandifo@gcc.gnu.org>2010-07-12 19:03:25 +0000
commitc371bb73807c48f1a708c51f113caea45f0347b1 (patch)
treefa440aa1ca8e5ec6721496213be7f7cdaa25daa9 /gcc/expmed.c
parentaa1c5d72e9cb30ddea2f930b6f94045dd8f2dcbc (diff)
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* expmed.h (alg_code, mult_cost, MULT_COST_LESS, CHEAPER_MULT_COST) (algorithm, alg_hash_entry, NUM_ALG_HASH_ENTRIES, alg_hash): Moved from expmed.c. (target_expmed): Add x_alg_hash and x_alg_hash_used_p. (alg_hash, alg_hash_used_p): New macros. * expmed.c (init_expmed): Clear alg_hash if reinitializing. (alg_code, mult_cost, MULT_COST_LESS, CHEAPER_MULT_COST, algorithm) (alg_hash_entry, NUM_ALG_HASH_ENTRIES, alg_hash): Moved to expmed.h. From-SVN: r162104
Diffstat (limited to 'gcc/expmed.c')
-rw-r--r--gcc/expmed.c111
1 files changed, 4 insertions, 107 deletions
diff --git a/gcc/expmed.c b/gcc/expmed.c
index c10d52e..186cf01 100644
--- a/gcc/expmed.c
+++ b/gcc/expmed.c
@@ -260,6 +260,10 @@ init_expmed (void)
}
}
}
+ if (alg_hash_used_p)
+ memset (alg_hash, 0, sizeof (alg_hash));
+ else
+ alg_hash_used_p = true;
default_rtl_profile ();
}
@@ -2283,113 +2287,6 @@ expand_shift (enum tree_code code, enum machine_mode mode, rtx shifted,
return temp;
}
-enum alg_code {
- alg_unknown,
- alg_zero,
- alg_m, alg_shift,
- alg_add_t_m2,
- alg_sub_t_m2,
- alg_add_factor,
- alg_sub_factor,
- alg_add_t2_m,
- alg_sub_t2_m,
- alg_impossible
-};
-
-/* This structure holds the "cost" of a multiply sequence. The
- "cost" field holds the total rtx_cost of every operator in the
- synthetic multiplication sequence, hence cost(a op b) is defined
- as rtx_cost(op) + cost(a) + cost(b), where cost(leaf) is zero.
- The "latency" field holds the minimum possible latency of the
- synthetic multiply, on a hypothetical infinitely parallel CPU.
- This is the critical path, or the maximum height, of the expression
- tree which is the sum of rtx_costs on the most expensive path from
- any leaf to the root. Hence latency(a op b) is defined as zero for
- leaves and rtx_cost(op) + max(latency(a), latency(b)) otherwise. */
-
-struct mult_cost {
- short cost; /* Total rtx_cost of the multiplication sequence. */
- short latency; /* The latency of the multiplication sequence. */
-};
-
-/* This macro is used to compare a pointer to a mult_cost against an
- single integer "rtx_cost" value. This is equivalent to the macro
- CHEAPER_MULT_COST(X,Z) where Z = {Y,Y}. */
-#define MULT_COST_LESS(X,Y) ((X)->cost < (Y) \
- || ((X)->cost == (Y) && (X)->latency < (Y)))
-
-/* This macro is used to compare two pointers to mult_costs against
- each other. The macro returns true if X is cheaper than Y.
- Currently, the cheaper of two mult_costs is the one with the
- lower "cost". If "cost"s are tied, the lower latency is cheaper. */
-#define CHEAPER_MULT_COST(X,Y) ((X)->cost < (Y)->cost \
- || ((X)->cost == (Y)->cost \
- && (X)->latency < (Y)->latency))
-
-/* This structure records a sequence of operations.
- `ops' is the number of operations recorded.
- `cost' is their total cost.
- The operations are stored in `op' and the corresponding
- logarithms of the integer coefficients in `log'.
-
- These are the operations:
- alg_zero total := 0;
- alg_m total := multiplicand;
- alg_shift total := total * coeff
- alg_add_t_m2 total := total + multiplicand * coeff;
- alg_sub_t_m2 total := total - multiplicand * coeff;
- alg_add_factor total := total * coeff + total;
- alg_sub_factor total := total * coeff - total;
- alg_add_t2_m total := total * coeff + multiplicand;
- alg_sub_t2_m total := total * coeff - multiplicand;
-
- The first operand must be either alg_zero or alg_m. */
-
-struct algorithm
-{
- struct mult_cost cost;
- short ops;
- /* The size of the OP and LOG fields are not directly related to the
- word size, but the worst-case algorithms will be if we have few
- consecutive ones or zeros, i.e., a multiplicand like 10101010101...
- In that case we will generate shift-by-2, add, shift-by-2, add,...,
- in total wordsize operations. */
- enum alg_code op[MAX_BITS_PER_WORD];
- char log[MAX_BITS_PER_WORD];
-};
-
-/* The entry for our multiplication cache/hash table. */
-struct alg_hash_entry {
- /* The number we are multiplying by. */
- unsigned HOST_WIDE_INT t;
-
- /* The mode in which we are multiplying something by T. */
- enum machine_mode mode;
-
- /* The best multiplication algorithm for t. */
- enum alg_code alg;
-
- /* The cost of multiplication if ALG_CODE is not alg_impossible.
- Otherwise, the cost within which multiplication by T is
- impossible. */
- struct mult_cost cost;
-
- /* OPtimized for speed? */
- bool speed;
-};
-
-/* The number of cache/hash entries. */
-#if HOST_BITS_PER_WIDE_INT == 64
-#define NUM_ALG_HASH_ENTRIES 1031
-#else
-#define NUM_ALG_HASH_ENTRIES 307
-#endif
-
-/* Each entry of ALG_HASH caches alg_code for some integer. This is
- actually a hash table. If we have a collision, that the older
- entry is kicked out. */
-static struct alg_hash_entry alg_hash[NUM_ALG_HASH_ENTRIES];
-
/* Indicates the type of fixup needed after a constant multiplication.
BASIC_VARIANT means no fixup is needed, NEGATE_VARIANT means that
the result should be negated, and ADD_VARIANT means that the