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| author | Richard Sandiford <richard.sandiford@linaro.org> | 2017-11-01 08:54:22 +0000 |
|---|---|---|
| committer | Richard Sandiford <rsandifo@gcc.gnu.org> | 2017-11-01 08:54:22 +0000 |
| commit | a9b76c8962410173ba0351b5b05b5f1f91742fc6 (patch) | |
| tree | 15cc0b6bcadb90da797eecab3ad626c487496ade | |
| parent | 6e0cb45f0c11d30f03498039b2f650ead28658bd (diff) | |
| download | gcc-a9b76c8962410173ba0351b5b05b5f1f91742fc6.zip gcc-a9b76c8962410173ba0351b5b05b5f1f91742fc6.tar.gz gcc-a9b76c8962410173ba0351b5b05b5f1f91742fc6.tar.bz2 | |
Prevent invalid register mode changes in combine
This patch stops combine from changing the mode of an existing register
in-place if doing so would change the size of the underlying register
allocation size, as given by REGMODE_NATURAL_SIZE. Without this,
many tests fail in adjust_reg_mode after SVE is added. One example
is gcc.c-torture/compile/20090401-1.c.
2017-11-01 Richard Sandiford <richard.sandiford@linaro.org>
Alan Hayward <alan.hayward@arm.com>
David Sherwood <david.sherwood@arm.com>
gcc/
* combine.c (can_change_dest_mode): Reject changes in
REGMODE_NATURAL_SIZE.
Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>
From-SVN: r254291
| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/combine.c | 6 |
2 files changed, 13 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 4c65319..1886218 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2017-11-01 Richard Sandiford <richard.sandiford@linaro.org> + Alan Hayward <alan.hayward@arm.com> + David Sherwood <david.sherwood@arm.com> + + * combine.c (can_change_dest_mode): Reject changes in + REGMODE_NATURAL_SIZE. + 2017-10-31 Sandra Loosemore <sandra@codesourcery.com> * configure.ac (--enable-libssp): New. diff --git a/gcc/combine.c b/gcc/combine.c index 93adfc1..4afae21 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -2478,6 +2478,12 @@ can_change_dest_mode (rtx x, int added_sets, machine_mode mode) != REGMODE_NATURAL_SIZE (GET_MODE (x))) return false; + /* Don't change between modes with different underlying register sizes, + since this could lead to invalid subregs. */ + if (REGMODE_NATURAL_SIZE (mode) + != REGMODE_NATURAL_SIZE (GET_MODE (x))) + return false; + regno = REGNO (x); /* Allow hard registers if the new mode is legal, and occupies no more registers than the old mode. */ |