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authorKenneth Zadeck <zadeck@naturalbridge.com>2009-11-04 23:17:54 +0000
committerKenneth Zadeck <zadeck@gcc.gnu.org>2009-11-04 23:17:54 +0000
commit4f2da32b77ba98bfe2430b7873b35ab6bcb49512 (patch)
treea3da37c593fe5498cc998681f5fb2a44272ca10f /gcc/df-scan.c
parentcb5f2074802fe0ca5668b6ec3f86cbaf01840637 (diff)
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df-scan.c (df-uses-record): Add case zero_extract of mem.
2009-11-04 Kenneth Zadeck <zadeck@naturalbridge.com> * df-scan.c (df-uses-record): Add case zero_extract of mem. From-SVN: r153924
Diffstat (limited to 'gcc/df-scan.c')
-rw-r--r--gcc/df-scan.c21
1 files changed, 17 insertions, 4 deletions
diff --git a/gcc/df-scan.c b/gcc/df-scan.c
index 45df29e..101234b 100644
--- a/gcc/df-scan.c
+++ b/gcc/df-scan.c
@@ -3248,10 +3248,23 @@ df_uses_record (enum df_ref_class cl, struct df_collection_rec *collection_rec,
width = INTVAL (XEXP (dst, 1));
offset = INTVAL (XEXP (dst, 2));
mode = GET_MODE (dst);
- df_uses_record (DF_REF_EXTRACT, collection_rec, &XEXP (dst, 0),
- DF_REF_REG_USE, bb, insn_info,
- DF_REF_READ_WRITE | DF_REF_ZERO_EXTRACT,
- width, offset, mode);
+ if (GET_CODE (XEXP (dst,0)) == MEM)
+ {
+ /* Handle the case of zero_extract(mem(...)) in the set dest.
+ This special case is allowed only if the mem is a single byte and
+ is useful to set a bitfield in memory. */
+ df_uses_record (DF_REF_EXTRACT, collection_rec, &XEXP (XEXP (dst,0), 0),
+ DF_REF_REG_MEM_STORE, bb, insn_info,
+ DF_REF_ZERO_EXTRACT,
+ width, offset, mode);
+ }
+ else
+ {
+ df_uses_record (DF_REF_EXTRACT, collection_rec, &XEXP (dst, 0),
+ DF_REF_REG_USE, bb, insn_info,
+ DF_REF_READ_WRITE | DF_REF_ZERO_EXTRACT,
+ width, offset, mode);
+ }
}
else
{