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re PR tree-optimization/63259 (Detecting byteswap sequence)

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2014-10-31  Thomas Preud'homme  <thomas.preudhomme@arm.com>

    gcc/
    PR tree-optimization/63259
    * tree-ssa-math-opts.c (bswap_replace): Replace expression by a
    rotation left if it is a 16 bit byte swap.
    (pass_optimize_bswap::execute): Also consider bswap in LROTATE_EXPR
    and RROTATE_EXPR statements if it is a byte rotation.

    gcc/testsuite/
    PR tree-optimization/63259
    * optimize-bswapsi-1.c (swap32_f): New bswap pass test.
    * optimize-bswaphi-1.c: Drop useless SIType definition and fix typo in
    following comment.

From-SVN: r216971
This commit is contained in:
Thomas Preud'homme 2014-10-31 11:55:07 +00:00 committed by Thomas Preud'homme
parent aed24d9d74
commit c6e3a93120
5 changed files with 68 additions and 15 deletions
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8
gcc/ChangeLog
View File

@ -1,3 +1,11 @@
2014-10-31 Thomas Preud'homme <thomas.preudhomme@arm.com>
PR tree-optimization/63259
* tree-ssa-math-opts.c (bswap_replace): Replace expression by a
rotation left if it is a 16 bit byte swap.
(pass_optimize_bswap::execute): Also consider bswap in LROTATE_EXPR
and RROTATE_EXPR statements if it is a byte rotation.
2014-10-31 Jakub Jelinek <jakub@redhat.com>
PR sanitizer/63697

7
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,10 @@
2014-10-31 Thomas Preud'homme <thomas.preudhomme@arm.com>
PR tree-optimization/63259
* optimize-bswapsi-1.c (swap32_f): New bswap pass test.
* optimize-bswaphi-1.c: Drop useless SIType definition and fix typo in
following comment.
2014-10-31 Jakub Jelinek <jakub@redhat.com>
PR sanitizer/63697

3
gcc/testsuite/gcc.dg/optimize-bswaphi-1.c
View File

@ -42,11 +42,10 @@ uint32_t read_be16_3 (unsigned char *data)
return *(data + 1) | (*data << 8);
}
typedef int SItype __attribute__ ((mode (SI)));
typedef int HItype __attribute__ ((mode (HI)));
/* Test that detection of significant sign extension works correctly. This
checks that unknown byte marker are set correctly in cast of cast. */
checks that unknown byte markers are set correctly in cast of cast. */
HItype
swap16 (HItype in)

13
gcc/testsuite/gcc.dg/optimize-bswapsi-1.c
View File

@ -78,5 +78,16 @@ swap32_e (SItype in)
| (((in >> 24) & 0xFF) << 0);
}
/* { dg-final { scan-tree-dump-times "32 bit bswap implementation found at" 5 "bswap" } } */
/* This variant comes from PR63259. It compiles to a gimple sequence that ends
with a rotation instead of a bitwise OR. */
unsigned
swap32_f (unsigned in)
{
in = ((in & 0xff00ff00) >> 8) | ((in & 0x00ff00ff) << 8);
in = ((in & 0xffff0000) >> 16) | ((in & 0x0000ffff) << 16);
return in;
}
/* { dg-final { scan-tree-dump-times "32 bit bswap implementation found at" 6 "bswap" } } */
/* { dg-final { cleanup-tree-dump "bswap" } } */

52
gcc/tree-ssa-math-opts.c
View File

@ -2187,7 +2187,7 @@ bswap_replace (gimple cur_stmt, gimple_stmt_iterator gsi, gimple src_stmt,
struct symbolic_number *n, bool bswap)
{
tree src, tmp, tgt;
gimple call;
gimple bswap_stmt;
src = gimple_assign_rhs1 (src_stmt);
tgt = gimple_assign_lhs (cur_stmt);
@ -2293,16 +2293,28 @@ bswap_replace (gimple cur_stmt, gimple_stmt_iterator gsi, gimple src_stmt,
tmp = src;
/* Convert the src expression if necessary. */
if (!useless_type_conversion_p (TREE_TYPE (tmp), bswap_type))
/* Canonical form for 16 bit bswap is a rotate expression. */
if (bswap && n->range == 16)
{
gimple convert_stmt;
tmp = make_temp_ssa_name (bswap_type, NULL, "bswapsrc");
convert_stmt = gimple_build_assign_with_ops (NOP_EXPR, tmp, src, NULL);
gsi_insert_before (&gsi, convert_stmt, GSI_SAME_STMT);
tree count = build_int_cst (NULL, BITS_PER_UNIT);
bswap_type = TREE_TYPE (src);
src = fold_build2 (LROTATE_EXPR, bswap_type, src, count);
bswap_stmt = gimple_build_assign (NULL, src);
}
else
{
/* Convert the src expression if necessary. */
if (!useless_type_conversion_p (TREE_TYPE (tmp), bswap_type))
{
gimple convert_stmt;
tmp = make_temp_ssa_name (bswap_type, NULL, "bswapsrc");
convert_stmt = gimple_build_assign_with_ops (NOP_EXPR, tmp, src,
NULL);
gsi_insert_before (&gsi, convert_stmt, GSI_SAME_STMT);
}
call = gimple_build_call (fndecl, 1, tmp);
bswap_stmt = gimple_build_call (fndecl, 1, tmp);
}
tmp = tgt;
@ -2315,7 +2327,7 @@ bswap_replace (gimple cur_stmt, gimple_stmt_iterator gsi, gimple src_stmt,
gsi_insert_after (&gsi, convert_stmt, GSI_SAME_STMT);
}
gimple_call_set_lhs (call, tmp);
gimple_set_lhs (bswap_stmt, tmp);
if (dump_file)
{
@ -2324,7 +2336,7 @@ bswap_replace (gimple cur_stmt, gimple_stmt_iterator gsi, gimple src_stmt,
print_gimple_stmt (dump_file, cur_stmt, 0, 0);
}
gsi_insert_after (&gsi, call, GSI_SAME_STMT);
gsi_insert_after (&gsi, bswap_stmt, GSI_SAME_STMT);
gsi_remove (&gsi, true);
return true;
}
@ -2388,13 +2400,29 @@ pass_optimize_bswap::execute (function *fun)
{
gimple src_stmt, cur_stmt = gsi_stmt (gsi);
tree fndecl = NULL_TREE, bswap_type = NULL_TREE, load_type;
enum tree_code code;
struct symbolic_number n;
bool bswap;
if (!is_gimple_assign (cur_stmt)
|| gimple_assign_rhs_code (cur_stmt) != BIT_IOR_EXPR)
if (!is_gimple_assign (cur_stmt))
continue;
code = gimple_assign_rhs_code (cur_stmt);
switch (code)
{
case LROTATE_EXPR:
case RROTATE_EXPR:
if (!tree_fits_uhwi_p (gimple_assign_rhs2 (cur_stmt))
|| tree_to_uhwi (gimple_assign_rhs2 (cur_stmt))
% BITS_PER_UNIT)
continue;
/* Fall through. */
case BIT_IOR_EXPR:
break;
default:
continue;
}
src_stmt = find_bswap_or_nop (cur_stmt, &n, &bswap);
if (!src_stmt)