This started out as an another attempt to find places where we had
things like:
offset_int x = wi::to_offset (...);
x = ...x...;
and change them to:
offset_int x = ...wi::to_offset (...)...;
with the get_ref_base_and_extent case being the main one.
But it turned out that some of them were also multiplying or
dividing by BITS_PER_UNIT, so it ended up also being a patch to
convert those to shifts.
I didn't want to cut-&-paste the 3 : log2 (BITS_PER_UNIT) conditional
yet more times, so I added a LOG2_BITS_PER_UNIT to defaults.h. I can
retrofit it to the existing code if that's OK at this stage.
For insn-recog.ii this reduces the number of divmod_internal calls from
7884858 to 369746.
Thanks,
Richard
Index: gcc/ChangeLog.wide-int
===================================================================
--- gcc/ChangeLog.wide-int 2013-11-29 15:09:59.623293132 +0000
+++ gcc/ChangeLog.wide-int 2013-11-29 15:11:48.611155898 +0000
@@ -111,6 +111,7 @@
(stabstr_U): Use wide-int interfaces.
(dbxout_type): Update to use cst_fits_shwi_p.
* defaults.h
+ (LOG2_BITS_PER_UNIT): Define.
(TARGET_SUPPORTS_WIDE_INT): Add default.
* dfp.c: Include wide-int.h.
(decimal_real_to_integer2): Use wide-int interfaces and rename to
Index: gcc/alias.c
===================================================================
--- gcc/alias.c 2013-11-29 15:04:41.136142237 +0000
+++ gcc/alias.c 2013-11-29 15:11:48.606155857 +0000
@@ -2355,8 +2355,8 @@ adjust_offset_for_component_ref (tree x,
offset_int woffset
= (wi::to_offset (xoffset)
- + wi::udiv_trunc (wi::to_offset (DECL_FIELD_BIT_OFFSET (field)),
- BITS_PER_UNIT));
+ + wi::lrshift (wi::to_offset (DECL_FIELD_BIT_OFFSET (field)),
+ LOG2_BITS_PER_UNIT));
if (!wi::fits_uhwi_p (woffset))
{
*known_p = false;
Index: gcc/defaults.h
===================================================================
--- gcc/defaults.h 2013-11-29 15:04:41.136142237 +0000
+++ gcc/defaults.h 2013-11-29 15:11:48.606155857 +0000
@@ -475,6 +475,14 @@ #define DWARF_TYPE_SIGNATURE_SIZE 8
#define BITS_PER_UNIT 8
#endif
+#if BITS_PER_UNIT == 8
+#define LOG2_BITS_PER_UNIT 3
+#elif BITS_PER_UNIT == 16
+#define LOG2_BITS_PER_UNIT 4
+#else
+#error Unknown BITS_PER_UNIT
+#endif
+
#ifndef BITS_PER_WORD
#define BITS_PER_WORD (BITS_PER_UNIT * UNITS_PER_WORD)
#endif
Index: gcc/dwarf2out.c
===================================================================
--- gcc/dwarf2out.c 2013-11-29 15:04:41.136142237 +0000
+++ gcc/dwarf2out.c 2013-11-29 15:40:56.188806688 +0000
@@ -14930,7 +14930,7 @@ field_byte_offset (const_tree decl)
object_offset_in_bits = bitpos_int;
object_offset_in_bytes
- = wi::udiv_trunc (object_offset_in_bits, BITS_PER_UNIT);
+ = wi::lrshift (object_offset_in_bits, LOG2_BITS_PER_UNIT);
return object_offset_in_bytes.to_shwi ();
}
Index: gcc/gimple-fold.c
===================================================================
--- gcc/gimple-fold.c 2013-11-29 15:04:41.136142237 +0000
+++ gcc/gimple-fold.c 2013-11-29 15:41:17.425983303 +0000
@@ -2926,7 +2926,6 @@ fold_nonarray_ctor_reference (tree type,
tree field_offset = DECL_FIELD_BIT_OFFSET (cfield);
tree field_size = DECL_SIZE (cfield);
offset_int bitoffset;
- offset_int byte_offset_cst = wi::to_offset (byte_offset);
offset_int bitoffset_end, access_end;
/* Variable sized objects in static constructors makes no sense,
@@ -2939,7 +2938,8 @@ fold_nonarray_ctor_reference (tree type,
/* Compute bit offset of the field. */
bitoffset = (wi::to_offset (field_offset)
- + byte_offset_cst * BITS_PER_UNIT);
+ + wi::lshift (wi::to_offset (byte_offset),
+ LOG2_BITS_PER_UNIT));
/* Compute bit offset where the field ends. */
if (field_size != NULL_TREE)
bitoffset_end = bitoffset + wi::to_offset (field_size);
Index: gcc/gimple-ssa-strength-reduction.c
===================================================================
--- gcc/gimple-ssa-strength-reduction.c 2013-11-29 15:04:41.136142237 +0000
+++ gcc/gimple-ssa-strength-reduction.c 2013-11-29 15:40:56.188806688 +0000
@@ -897,7 +897,7 @@ restructure_reference (tree *pbase, tree
c2 = 0;
}
- c4 = wi::udiv_floor (index, BITS_PER_UNIT);
+ c4 = wi::lrshift (index, LOG2_BITS_PER_UNIT);
c5 = backtrace_base_for_ref (&t2);
*pbase = t1;
Index: gcc/tree-dfa.c
===================================================================
--- gcc/tree-dfa.c 2013-11-29 15:04:41.136142237 +0000
+++ gcc/tree-dfa.c 2013-11-29 15:41:39.513166464 +0000
@@ -437,10 +437,8 @@ get_ref_base_and_extent (tree exp, HOST_
if (this_offset && TREE_CODE (this_offset) == INTEGER_CST)
{
- offset_int woffset = wi::to_offset (this_offset);
- woffset = wi::lshift (woffset,
- (BITS_PER_UNIT == 8
- ? 3 : exact_log2 (BITS_PER_UNIT)));
+ offset_int woffset = wi::lshift (wi::to_offset (this_offset),
+ LOG2_BITS_PER_UNIT);
woffset += wi::to_offset (DECL_FIELD_BIT_OFFSET (field));
bit_offset += woffset;
@@ -505,9 +503,7 @@ get_ref_base_and_extent (tree exp, HOST_
= wi::sext (wi::to_offset (index) - wi::to_offset (low_bound),
TYPE_PRECISION (TREE_TYPE (index)));
woffset *= wi::to_offset (unit_size);
- woffset = wi::lshift (woffset,
- (BITS_PER_UNIT == 8
- ? 3 : exact_log2 (BITS_PER_UNIT)));
+ woffset = wi::lshift (woffset, LOG2_BITS_PER_UNIT);
bit_offset += woffset;
/* An array ref with a constant index up in the structure
Index: gcc/tree-ssa-alias.c
===================================================================
--- gcc/tree-ssa-alias.c 2013-11-29 15:04:41.136142237 +0000
+++ gcc/tree-ssa-alias.c 2013-11-29 15:11:48.605155849 +0000
@@ -2127,18 +2127,19 @@ stmt_kills_ref_p_1 (gimple stmt, ao_ref
if (TREE_CODE (rbase) != MEM_REF)
return false;
// Compare pointers.
- offset += mem_ref_offset (base) * BITS_PER_UNIT;
- roffset += mem_ref_offset (rbase) * BITS_PER_UNIT;
+ offset += wi::lshift (mem_ref_offset (base),
+ LOG2_BITS_PER_UNIT);
+ roffset += wi::lshift (mem_ref_offset (rbase),
+ LOG2_BITS_PER_UNIT);
base = TREE_OPERAND (base, 0);
rbase = TREE_OPERAND (rbase, 0);
}
- if (base == rbase)
- {
- offset_int size = wi::to_offset (len) * BITS_PER_UNIT;
- if (wi::les_p (offset, roffset)
- && wi::les_p (roffset + ref->max_size, offset + size))
- return true;
- }
+ if (base == rbase
+ && wi::les_p (offset, roffset)
+ && wi::les_p (roffset + ref->max_size,
+ offset + wi::lshift (wi::to_offset (len),
+ LOG2_BITS_PER_UNIT)))
+ return true;
break;
}
