Commit Graph

7 Commits

Author SHA1 Message Date
Bill Schmidt
551a3d7b56 [PowerPC] Clean up -mattr=+vsx tests to always specify -mcpu
We recently discovered an issue that reinforces what a good idea it is
to always specify -mcpu in our code generation tests, particularly for
-mattr=+vsx.  This patch ensures that all tests that specify
-mattr=+vsx also specify -mcpu=pwr7 or -mcpu=pwr8, as appropriate.

Some of the uses of -mattr=+vsx added recently don't make much sense
(when specified for -mtriple=powerpc-apple-darwin8 or -march=ppc32,
for example).  For cases like this I've just removed the extra VSX
test commands; there's enough coverage without them.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220173 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-19 21:29:21 +00:00
Bill Schmidt
b76f5ba103 [PowerPC] Enable use of lxvw4x/stxvw4x in VSX code generation
Currently the VSX support enables use of lxvd2x and stxvd2x for 2x64
types, but does not yet use lxvw4x and stxvw4x for 4x32 types.  This
patch adds that support.

As with lxvd2x/stxvd2x, this involves straightforward overriding of
the patterns normally recognized for lvx/stvx, with preference given
to the VSX patterns when VSX is enabled.

In addition, the logic for permitting misaligned memory accesses is
modified so that v4r32 and v4i32 are treated the same as v2f64 and
v2i64 when VSX is enabled.  Finally, the DAG generation for unaligned
loads is changed to just use a normal LOAD (which will become lxvw4x)
on P8 and later hardware, where unaligned loads are preferred over
lvsl/lvx/lvx/vperm.

A number of tests now generate the VSX loads/stores instead of
lvx/stvx, so this patch adds VSX variants to those tests.  I've also
added <4 x float> tests to the vsx.ll test case, and created a
vsx-p8.ll test case to be used for testing code generation for the
P8Vector feature.  For now, that simply tests the unaligned load/store
behavior.

This has been tested along with a temporary patch to enable the VSX
and P8Vector features, with no new regressions encountered with or
without the temporary patch applied.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220047 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-17 15:13:38 +00:00
Bill Schmidt
11729224bf [PowerPC] Disable fast-isel for existing -O0 tests for PowerPC.
This is a preliminary patch for fast instruction selection on
PowerPC.  Code generation can differ between DAG isel and fast isel.
Existing tests that specify -O0 were written to expect DAG isel.  Make
this explicit by adding -fast-isel=false to the tests.

In some cases specifying -fast-isel=false produces different code even
when there isn't a fast instruction selector specified.  This is
because TM.Options.EnableFastISel = 1 at -O0 whether or not a FastISel
object exists.  Thus disabling fast isel can actually produce less
conservative code.  Because of this, some of the expected code
generation in the -O0 tests needs to be adjusted.

In particular, handling of function arguments is less conservative
with -fast-isel=false (see isOnlyUsedInEntryBlock() in
SelectionDAGBuilder.cpp).  This results in fewer stack accesses and,
in some cases, reduced stack size as uselessly loaded values are no
longer stored back to spill locations in the stack.

No functional change with this patch; test case adjustments only.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183939 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-13 20:23:34 +00:00
Hal Finkel
3249729043 Improve PPC VR (Altivec) register spilling
This change cleans up two issues with Altivec register spilling:

  1. The spilling code was inefficient (using two instructions, and add and a
     load, when just one would do)

  2. The code assumed that r0 would always be available (true for now, but this
     will change)

The new code handles VR spilling just like GPR spills but forced into r+r mode.
As a result, when any VR spills are present, we must now always allocate the
register-scavenger spill slot.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177231 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-17 04:43:44 +00:00
Bill Schmidt
e0bc37579b Add -mattr=+altivec and remove XFAIL.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165666 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 22:25:11 +00:00
Bill Schmidt
3a55b64e5e XFAIL for all targets pending investigation
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165664 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 21:52:10 +00:00
Bill Schmidt
26160f4e64 When generating spill and reload code for vector registers on PowerPC,
the compiler makes use of GPR0.  However, there are two flavors of
GPR0 defined by the target:  the 32-bit GPR0 (R0) and the 64-bit GPR0
(X0).  The spill/reload code makes use of R0 regardless of whether we
are generating 32- or 64-bit code.

This patch corrects the problem in the obvious manner, using X0 and
ADDI8 for 64-bit and R0 and ADDI for 32-bit.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165658 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 21:25:01 +00:00