diff options
| author | Meador Inge <meadori@codesourcery.com> | 2012-05-18 09:04:38 +0000 |
|---|---|---|
| committer | Richard Sandiford <rsandifo@gcc.gnu.org> | 2012-05-18 09:04:38 +0000 |
| commit | 7cb6668a1f251a35f26875398992eb4b1ae78f30 (patch) | |
| tree | 91ed913d04c3205957d44e36e2b7751a0fd287dd /gcc/cse.c | |
| parent | 4a3afb1a3d9959742fc9279ffba9f9acd994d8f2 (diff) | |
| download | gcc-7cb6668a1f251a35f26875398992eb4b1ae78f30.zip gcc-7cb6668a1f251a35f26875398992eb4b1ae78f30.tar.gz gcc-7cb6668a1f251a35f26875398992eb4b1ae78f30.tar.bz2 | |
re PR rtl-optimization/53352 (Incorrect CSE optimization on RTL expressions with a paradoxical subreg)
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.
From-SVN: r187648
Diffstat (limited to 'gcc/cse.c')
| -rw-r--r-- | gcc/cse.c | 6 |
1 files changed, 5 insertions, 1 deletions
@@ -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)); |