diff options
| author | Meador Inge <meadori@codesourcery.com> | 2012-05-18 09:04:38 +0000 |
|---|---|---|
| committer | Richard Sandiford <r.sandiford@uk.ibm.com> | 2012-05-18 09:04:38 +0000 |
| commit | b63be8372a2d4c59dbf896189ad011853bb32e87 (patch) | |
| tree | 91ed913d04c3205957d44e36e2b7751a0fd287dd /gcc/cse.c | |
| parent | 82495146f112df1a0db5336c70a598210d74b762 (diff) | |
gcc/
2012-05-15 Meador Inge <meadori@codesourcery.com>
PR rtl-optimization/53352
* cse.c (equiv_constant): Ignore paradoxical subregs.
gcc/testsuite/
2012-05-15 Meador Inge <meadori@codesourcery.com>
PR rtl-optimization/53352
* gcc.dg/pr53352.c: New test.
git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@187648 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/cse.c')
| -rw-r--r-- | gcc/cse.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/gcc/cse.c b/gcc/cse.c index 0ad7b2e2a46..9f4e97932ed 100644 --- a/gcc/cse.c +++ b/gcc/cse.c @@ -3786,8 +3786,12 @@ equiv_constant (rtx x) } } - /* Otherwise see if we already have a constant for the inner REG. */ + /* Otherwise see if we already have a constant for the inner REG, + and if that is enough to calculate an equivalent constant for + the subreg. Note that the upper bits of paradoxical subregs + are undefined, so they cannot be said to equal anything. */ if (REG_P (SUBREG_REG (x)) + && GET_MODE_SIZE (mode) <= GET_MODE_SIZE (imode) && (new_rtx = equiv_constant (SUBREG_REG (x))) != 0) return simplify_subreg (mode, new_rtx, imode, SUBREG_BYTE (x)); |