2 Commits

Author SHA1 Message Date
Tim Northover
15983b80a0 X86: use sub-register sequences for MOV*r0 operations
Instead of having a bunch of separate MOV8r0, MOV16r0, ... pseudo-instructions,
it's better to use a single MOV32r0 (which will expand to "xorl %reg, %reg")
and obtain other sizes with EXTRACT_SUBREG and SUBREG_TO_REG. The encoding is
smaller and partial register updates can sometimes be avoided.

Until recently, this sequence was a barrier to rematerialization though. That
should now be fixed so it's an appropriate time to make the change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182928 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-30 13:19:42 +00:00
Eli Bendersky
50125482d3 This patch teaches x86 fast-isel to generate the native div/idiv instructions
for the sdiv/srem/udiv/urem bitcode instructions.  This is done for the i8,
i16, and i32 types, as well as i64 for the x86_64 target.

Patch by Jim Stichnoth



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179715 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-17 20:10:13 +00:00