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| author | Segher Boessenkool <segher@kernel.crashing.org> | 2016-11-29 06:44:32 +0100 |
|---|---|---|
| committer | Segher Boessenkool <segher@gcc.gnu.org> | 2016-11-29 06:44:32 +0100 |
| commit | 452385a7205e963d02890bae566ba523a977c877 (patch) | |
| tree | 7b3a30880172d82e63478ec3f74e42ce6e209167 /gcc | |
| parent | dfed7971fb42cbd5196ee92e27e8292f46fa72e9 (diff) | |
| download | gcc-452385a7205e963d02890bae566ba523a977c877.zip gcc-452385a7205e963d02890bae566ba523a977c877.tar.gz gcc-452385a7205e963d02890bae566ba523a977c877.tar.bz2 | |
combine: Tweak change_zero_ext
change_zero_ext handles (zero_extend:M1 (subreg:M2 (reg:M1) ...))
already; this patch extends it to also deal with any
(zero_extend:M1 (subreg:M2 (reg:M3) ...)) where the subreg is not
paradoxical.
* combine.c (change_zero_ext): Also handle extends from a subreg
to a mode bigger than that of the operand of the subreg.
From-SVN: r242950
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/combine.c | 4 |
2 files changed, 8 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 27f4137..5ef1fcc 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,10 @@ 2016-11-29 Segher Boessenkool <segher@kernel.crashing.org> + * combine.c (change_zero_ext): Also handle extends from a subreg + to a mode bigger than that of the operand of the subreg. + +2016-11-29 Segher Boessenkool <segher@kernel.crashing.org> + PR target/77687 * config/rs6000/rs6000.c (rs6000_emit_stack_reset): Emit the stack_restore_tie insn instead of stack_tie, for the SVR4 and diff --git a/gcc/combine.c b/gcc/combine.c index 41f69da..22fb7a9 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -11251,11 +11251,13 @@ change_zero_ext (rtx pat) else if (GET_CODE (x) == ZERO_EXTEND && SCALAR_INT_MODE_P (mode) && GET_CODE (XEXP (x, 0)) == SUBREG - && GET_MODE (SUBREG_REG (XEXP (x, 0))) == mode + && !paradoxical_subreg_p (XEXP (x, 0)) && subreg_lowpart_p (XEXP (x, 0))) { size = GET_MODE_PRECISION (GET_MODE (XEXP (x, 0))); x = SUBREG_REG (XEXP (x, 0)); + if (GET_MODE (x) != mode) + x = gen_lowpart_SUBREG (mode, x); } else if (GET_CODE (x) == ZERO_EXTEND && SCALAR_INT_MODE_P (mode) |