Commit Graph

4 Commits

Author SHA1 Message Date
Andrew Wei 992698cfbc [AArch64] Emit zext move when the source of the zext is AssertZext or AssertSext
When the source of the zext is AssertZext or AssertSext, it is hard to know any information about the upper 32 bits,
so we should insert a zext move before emitting SUBREG_TO_REG to define the lower 32 bits.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D87771
2020-09-18 12:48:41 +08:00
Jessica Paquette ceb801612a [AArch64] Don't generate libcalls for wide shifts on Darwin
Similar to cff90f07cb.

Darwin doesn't always use compiler-rt, and so we can't assume that these
functions are available (at least on arm64).
2020-01-10 15:58:51 -08:00
Hans Wennborg cff90f07cb [SelectionDAG] Don't generate libcalls for wide shifts on Windows (PR42711)
Neither libgcc or compiler-rt are usually used on Windows, so these
functions can't be called.

Differential revision: https://reviews.llvm.org/D66880

llvm-svn: 370204
2019-08-28 13:55:10 +00:00
Sjoerd Meijer f7cc34cae8 [SelectionDAG] Codesize: don't expand SHIFT to SHIFT_PARTS
And instead just generate a libcall. My motivating example on ARM was a simple:
  
  shl i64 %A, %B

for which the code bloat is quite significant. For other targets that also
accept __int128/i128 such as AArch64 and X86, it is also beneficial for these
cases to generate a libcall when optimising for minsize. On these 64-bit targets,
the 64-bits shifts are of course unaffected because the SHIFT/SHIFT_PARTS
lowering operation action is not set to custom/expand.

Differential Revision: https://reviews.llvm.org/D57386

llvm-svn: 352736
2019-01-31 08:07:30 +00:00