Commit Graph

55 Commits

Author SHA1 Message Date
Richard Sandiford d131ff8cf8 [SystemZ] Use MVC for memcpy
Use MVC for memcpy in cases where a single MVC is enough.  Using MVC is
a win for longer copies too, but I'll leave that for later.

llvm-svn: 185802
2013-07-08 09:35:23 +00:00
Richard Sandiford e6e7885591 [SystemZ] Use DSGFR over DSGR in more cases
Fixes some cases where we were using full 64-bit division for (sdiv i32, i32)
and (sdiv i64, i32).

The "32" in "SDIVREM32" just refers to the second operand.  The first operand
of all *DIVREM*s is a GR128.

llvm-svn: 185435
2013-07-02 15:40:22 +00:00
Richard Sandiford b86a83488e [SystemZ] Add conditional store patterns
Add pseudo conditional store instructions, so that we use:

    branch foo:
    store
foo:

instead of:

    load
    branch foo:
    move
foo:
    store

z196 has real 32-bit and 64-bit conditional stores, but we don't use
any z196 instructions yet.

llvm-svn: 185065
2013-06-27 09:27:40 +00:00
Richard Sandiford 30efd87f6e [SystemZ] Don't use LOAD and STORE REVERSED for volatile accesses
Unlike most -- hopefully "all other", but I'm still checking -- memory
instructions we support, LOAD REVERSED and STORE REVERSED may access
the memory location several times.  This means that they are not suitable
for volatile loads and stores.

This patch is a prerequisite for better atomic load and store support.
The same principle applies there: almost all memory instructions we
support are inherently atomic ("block concurrent"), but LOAD REVERSED
and STORE REVERSED are exceptions.

Other instructions continue to allow volatile operands.  I will add
positive "allows volatile" tests at the same time as the "allows atomic
load or store" tests.

llvm-svn: 183002
2013-05-31 13:25:22 +00:00
Ulrich Weigand 5f613dfd1f [SystemZ] Add back end
This adds the actual lib/Target/SystemZ target files necessary to
implement the SystemZ target.  Note that at this point, the target
cannot yet be built since the configure bits are missing.  Those
will be provided shortly by a follow-on patch.

This version of the patch incorporates feedback from reviews by
Chris Lattner and Anton Korobeynikov.  Thanks to all reviewers!

Patch by Richard Sandiford.

llvm-svn: 181203
2013-05-06 16:15:19 +00:00