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| author | Richard Kenner <kenner@gcc.gnu.org> | 1994-01-22 15:50:06 -0500 |
|---|---|---|
| committer | Richard Kenner <kenner@gcc.gnu.org> | 1994-01-22 15:50:06 -0500 |
| commit | 0c314d1ab0636a2253dfc8b4f9f50010210556dc (patch) | |
| tree | 777408b38b27ff8769acbfc3f77349fc573c111d /gcc | |
| parent | abb6b720734c1fb17251defde364f9b1e39ebcfb (diff) | |
| download | gcc-0c314d1ab0636a2253dfc8b4f9f50010210556dc.zip gcc-0c314d1ab0636a2253dfc8b4f9f50010210556dc.tar.gz gcc-0c314d1ab0636a2253dfc8b4f9f50010210556dc.tar.bz2 | |
(num_sign_bit_copies): Ifndef WORD_REGISTER_OPERATIONS, ensure we
don't do the wrong thing if X is narrower than MODE.
From-SVN: r6403
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/combine.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index a71b201..729d557 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -1,5 +1,5 @@ /* Optimize by combining instructions for GNU compiler. - Copyright (C) 1987, 1988, 1992, 1993 Free Software Foundation, Inc. + Copyright (C) 1987, 1988, 1992, 1993, 1994 Free Software Foundation, Inc. This file is part of GNU CC. @@ -6965,6 +6965,14 @@ num_sign_bit_copies (x, mode) return MAX (1, (num_sign_bit_copies (x, GET_MODE (x)) - (GET_MODE_BITSIZE (GET_MODE (x)) - bitwidth))); +#ifndef WORD_REGISTER_OPERATIONS + /* If this machine does not do all register operations on the entire + register and MODE is wider than the mode of X, we can say nothing + at all about the high-order bits. */ + if (GET_MODE (x) != VOIDmode && bitwidth > GET_MODE_BITSIZE (GET_MODE (x))) + return 1; +#endif + switch (code) { case REG: |