alignment_for_piecewise_move is called only with MOVE_MAX_PIECES or
STORE_MAX_PIECES, which are the number of bytes at a time that we
can move or store efficiently. We should call mode_for_size without
limit to MAX_FIXED_MODE_SIZE, which is an integer expression for the
size in bits of the largest integer machine mode that should actually
be used, may be smaller than MOVE_MAX_PIECES or STORE_MAX_PIECES, which
may use vector register.
MAX_BITSIZE_MODE_ANY_INT is only defined for i386 and everyone else uses
the default. The widest mode for integer computation is determined by
MAX_FIXED_MODE_SIZE, not by MAX_BITSIZE_MODE_ANY_INT. OImode and XImode
can be used for load and store, including constant integers. Remove
MAX_BITSIZE_MODE_ANY_INT from i386 to avoid any potential problems for
constant integers > TImode.
Tested on i686 and x86-64. OK for trunk?
H.J.
---
PR middle-end/74113
* expr.c (alignment_for_piecewise_move): Call mode_for_size
without limit to MAX_FIXED_MODE_SIZE.
* config/i386/i386-modes.def (MAX_BITSIZE_MODE_ANY_INT): Removed.
---
gcc/config/i386/i386-modes.def | 5 -----
gcc/expr.c | 2 +-
2 files changed, 1 insertion(+), 6 deletions(-)
diff --git a/gcc/config/i386/i386-modes.def b/gcc/config/i386/i386-modes.def
index d524313..61a1f08 100644
--- a/gcc/config/i386/i386-modes.def
+++ b/gcc/config/i386/i386-modes.def
@@ -98,10 +98,5 @@ POINTER_BOUNDS_MODE (BND64, 16);
INT_MODE (OI, 32);
INT_MODE (XI, 64);
-/* Keep the OI and XI modes from confusing the compiler into thinking
- that these modes could actually be used for computation. They are
- only holders for vectors during data movement. */
-#define MAX_BITSIZE_MODE_ANY_INT (128)
-
/* The symbol Pmode stands for one of the above machine modes (usually SImode).
The tm.h file specifies which one. It is not a distinct mode. */
diff --git a/gcc/expr.c b/gcc/expr.c
index 46de35f..826fd9b 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -692,7 +692,7 @@ alignment_for_piecewise_move (unsigned int max_pieces,
unsigned int align)
{
machine_mode tmode;
- tmode = mode_for_size (max_pieces * BITS_PER_UNIT, MODE_INT, 1);
+ tmode = mode_for_size (max_pieces * BITS_PER_UNIT, MODE_INT, 0);
if (align >= GET_MODE_ALIGNMENT (tmode))
align = GET_MODE_ALIGNMENT (tmode);
else
--
2.7.4
