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author | Richard Sandiford <rdsandiford@googlemail.com> | 2010-07-12 19:03:25 +0000 |
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committer | Richard Sandiford <rsandifo@gcc.gnu.org> | 2010-07-12 19:03:25 +0000 |
commit | c371bb73807c48f1a708c51f113caea45f0347b1 (patch) | |
tree | fa440aa1ca8e5ec6721496213be7f7cdaa25daa9 /gcc/expmed.c | |
parent | aa1c5d72e9cb30ddea2f930b6f94045dd8f2dcbc (diff) | |
download | gcc-c371bb73807c48f1a708c51f113caea45f0347b1.zip gcc-c371bb73807c48f1a708c51f113caea45f0347b1.tar.gz gcc-c371bb73807c48f1a708c51f113caea45f0347b1.tar.bz2 |
gcc/
* 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.c | 111 |
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 |