"For ARM stack frames that utilize variable sized objects and have either
large local stack areas or require dynamic stack realignment, allocate a
base register via which to access the local frame. This allows efficient
access to frame indices not accessible via the FP (either due to being out
of range or due to dynamic realignment) or the SP (due to variable sized
object allocation). In particular, this greatly improves efficiency of access
to spill slots in Thumb functions which contain VLAs."
r112986 fixed a latent bug exposed by the above.
llvm-svn: 112989
large local stack areas or require dynamic stack realignment, allocate a
base register via which to access the local frame. This allows efficient
access to frame indices not accessible via the FP (either due to being out
of range or due to dynamic realignment) or the SP (due to variable sized
object allocation). In particular, this greatly improves efficiency of access
to spill slots in Thumb functions which contain VLAs.
rdar://7352504
rdar://8374540
rdar://8355680
llvm-svn: 112883
memory and synchronization barrier dmb and dsb instructions.
- Change instruction names to something more sensible (matching name of actual
instructions).
- Added tests for memory barrier codegen.
llvm-svn: 110785
Also added a test case to check for the added benefit of this patch: it's optimizing away the unnecessary restore of sp from fp for some non-leaf functions.
llvm-svn: 110707
reserved, not available for general allocation. This eliminates all the
extra checks for Darwin.
This change also fixes the use of FP to access frame indices in leaf
functions and cleaned up some confusing code in epilogue emission.
llvm-svn: 110655
occasions, caused code to be generated in a different order.
All cases I've seen involved float softening in the type
legalizer, and this could be perhaps be fixed there, but
it's better not to generate things differently in the first
place. 7797940 (6/29/2010..7/15/2010).
llvm-svn: 108484
PrologEpilog code, and use it to determine whether
the asm forces stack alignment or not. gcc consistently
does not do this for GCC-style asms; Apple gcc inconsistently
sometimes does it for asm blocks. There is no
convenient place to put a bit in either the SDNode or
the MachineInstr form, so I've added an extra operand
to each; unlovely, but it does allow for expansion for
more bits, should we need it. PR 5125. Some
existing testcases are affected.
The operand lists of the SDNode and MachineInstr forms
are indexed with awesome mnemonics, like "2"; I may
fix this someday, but not now. I'm not making it any
worse. If anyone is inspired I think you can find all
the right places from this patch.
llvm-svn: 107506
getFunctionAlignment and the corresponding use of that value in the ARM
asm printer, but now we're using the standard asm printer. The result of
this was that function alignments were dropped completely for Thumb functions.
Radar 8143571.
llvm-svn: 107435
