MatCat.OpenSource/8sa1-gcc
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

(subst): For subreg-of-constant, don't gen_lowpart

Browse Source 
if it's a big-endian machine and constant is multi-word.

From-SVN: r4554
This commit is contained in:
Richard Stallman 1993-05-24 07:45:54 +00:00
parent 87d11e4386
commit 19808e22ca
1 changed files with 9 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
gcc/combine.c
View File

@ -3085,8 +3085,16 @@ subst (x, from, to, in_dest, unique_copy)
return temp;
}
/* If we want a subreg of a constant, at offset 0,
take the low bits. On a little-endian machine, that's
always valid. On a big-endian machine, it's valid
only if the constant's mode fits in one word. */
if (CONSTANT_P (SUBREG_REG (x)) && subreg_lowpart_p (x)
&& GET_MODE_SIZE (mode) < GET_MODE_SIZE (op0_mode))
&& GET_MODE_SIZE (mode) < GET_MODE_SIZE (op0_mode)
#if WORDS_BIG_ENDIAN
&& GET_MODE_BITSIZE (op0_mode) < BITS_PER_WORD
#endif
)
return gen_lowpart_for_combine (mode, SUBREG_REG (x));
/* If we are narrowing the object, we need to see if we can simplify