Commit Graph

4 Commits

Author SHA1 Message Date
James Y Knight 2e64b8b79e [Sparc] Don't overlap variable-sized allocas with other stack variables.
On SparcV8, it was previously the case that a variable-sized alloca
might overlap by 4-bytes the last fixed stack variable, effectively
because 92 (the number of bytes reserved for the register spill area) !=
96 (the offset added to SP for where to start a DYNAMIC_STACKALLOC).

It's not as simple as changing 96 to 92, because variables that should
be 8-byte aligned would then be misaligned.

For now, simply increase the allocation size by 8 bytes for each dynamic
allocation -- wastes space, but at least doesn't overlap. As the large
comment says, doing this more efficiently will require larger changes in
llvm.

Also adds some test cases showing that we continue to not support
dynamic stack allocation and over-alignment in the same function.

llvm-svn: 285131
2016-10-25 22:13:28 +00:00
Venkatraman Govindaraju 61116e7084 [SPARCV9]: Adjust the resultant pointer of DYNAMIC_STACKALLOC with the stack BIAS on sparcV9.
llvm-svn: 196755
2013-12-09 05:13:25 +00:00
Venkatraman Govindaraju 0510db0597 [SparcV9] Enable custom lowering of DYNAMIC_STACKALLOC in sparc64.
llvm-svn: 195573
2013-11-24 17:41:41 +00:00
Venkatraman Govindaraju 641b0b5a21 [Sparc] Implements hasReservedCallFrame and hasFP.
This is to generate correct framesetup code when the function
 has variable sized allocas.

llvm-svn: 182108
2013-05-17 15:14:34 +00:00