Commit Graph

13 Commits

Author SHA1 Message Date
Stefan Pintilie 6262fd4b0a Revert "[PowerPC] Try to simplify a Swap if it feeds a Splat"
Revert r316478.
A test case has failed.
Will recommit this change once we find and fix the failure.

This reverts commit 7c330fabaedaba3d02c58bc3cc1198896c895f34.

llvm-svn: 316952
2017-10-30 19:55:38 +00:00
Stefan Pintilie 8f0c783095 [PowerPC] Try to simplify a Swap if it feeds a Splat
If we have the situation where a Swap feeds a Splat we can sometimes change the
  index on the Splat and then remove the Swap instruction.

Fixed the test case that was failing and recommit after pulling the original
  commit.

  Original revision is here: https://reviews.llvm.org/D39009

llvm-svn: 316478
2017-10-24 17:44:27 +00:00
Hiroshi Inoue e3a3e3c9e9 [PowerPC] Eliminate sign- and zero-extensions if already sign- or zero-extended
This patch enables redundant sign- and zero-extension elimination in PowerPC MI Peephole pass.
If the input value of a sign- or zero-extension is known to be already sign- or zero-extended, the operation is redundant and can be eliminated.
One common case is sign-extensions for a method parameter or for a method return value; they must be sign- or zero-extended as defined in PPC ELF ABI. 
For example of the following simple code, two extsw instructions are generated before the invocation of int_func and before the return. With this patch, both extsw are eliminated.

void int_func(int);
void ii_test(int a) {
    if (a & 1) return int_func(a);
}

Such redundant sign- or zero-extensions are quite common in many programs; e.g. I observed about 60,000 occurrences of the elimination while compiling the LLVM+CLANG.

Differential Revision: https://reviews.llvm.org/D31319

llvm-svn: 315888
2017-10-16 04:12:57 +00:00
Nemanja Ivanovic ffcf0fb1cc [PowerPC][Altivec] Add mfvrd and mffprd extended mnemonic
mfvrd and mffprd are both alias to mfvrsd.
This patch enables correct parsing of the aliases, but we still emit a mfvrsd.

Committing on behalf of brunoalr (Bruno Rosa).

Differential Revision: https://reviews.llvm.org/D29177

llvm-svn: 297849
2017-03-15 16:04:53 +00:00
Nemanja Ivanovic df1cb520df [PowerPC] Improvements for BUILD_VECTOR Vol. 1
This patch corresponds to review:
https://reviews.llvm.org/D25912

This is the first patch in a series of 4 that improve the lowering and combining
for BUILD_VECTOR nodes on PowerPC.

llvm-svn: 288152
2016-11-29 16:11:34 +00:00
Nemanja Ivanovic 11049f8f07 [Power9] Part-word VSX integer scalar loads/stores and sign extend instructions
This patch corresponds to review:
https://reviews.llvm.org/D23155

This patch removes the VSHRC register class (based on D20310) and adds
exploitation of the Power9 sub-word integer loads into VSX registers as well
as vector sign extensions.
The new instructions are useful for a few purposes:

    Int to Fp conversions of 1 or 2-byte values loaded from memory
    Building vectors of 1 or 2-byte integers with values loaded from memory
    Storing individual 1 or 2-byte elements from integer vectors

This patch implements all of those uses.

llvm-svn: 283190
2016-10-04 06:59:23 +00:00
Nemanja Ivanovic eebbcb6d57 [PowerPC] Cannonicalize applicable vector shift immediates as swaps
This patch corresponds to review:
http://reviews.llvm.org/D21358

Vector shifts that have the same semantics as a vector swap are cannonicalized
as such to provide additional opportunities for swap removal optimization to
remove unnecessary swaps.

llvm-svn: 275168
2016-07-12 12:16:27 +00:00
Nemanja Ivanovic ac8d01add0 Bitcasts between FP and INT values using direct moves
This patch corresponds to review:
http://reviews.llvm.org/D15286

LLVM IR frequently contains bitcast operations between floating point and
integer values of the same width. Doing this through memory operations is
quite expensive on PPC. This patch allows the use of direct register moves
between FPRs and GPRs for lowering bitcasts.

llvm-svn: 255246
2015-12-10 13:35:28 +00:00
Bill Schmidt 34af5e1c76 [PowerPC] Add an MI SSA peephole pass.
This patch adds a pass for doing PowerPC peephole optimizations at the
MI level while the code is still in SSA form.  This allows for easy
modifications to the instructions while depending on a subsequent pass
of DCE.  Both passes are very fast due to the characteristics of SSA.

At this time, the only peepholes added are for cleaning up various
redundancies involving the XXPERMDI instruction.  However, I would
expect this will be a useful place to add more peepholes for
inefficiencies generated during instruction selection.  The pass is
placed after VSX swap optimization, as it is best to let that pass
remove unnecessary swaps before performing any remaining clean-ups.

The utility of these clean-ups are demonstrated by changes to four
existing test cases, all of which now have tighter expected code
generation.  I've also added Eric Schweiz's bugpoint-reduced test from
PR25157, for which we now generate tight code.  One other test started
failing for me, and I've fixed it
(test/Transforms/PlaceSafepoints/finite-loops.ll) as well; this is not
related to my changes, and I'm not sure why it works before and not
after.  The problem is that the CHECK-NOT: of "statepoint" from test1
fails because of the "statepoint" in test2, and so forth.  Adding a
CHECK-LABEL in between keeps the different occurrences of that string
properly scoped.

llvm-svn: 252651
2015-11-10 21:38:26 +00:00
Nemanja Ivanovic be5f0c04f1 Fix for bootstrap bug introduced in r244921
This revision has introduced an issue that only affects bootstrapped compiler
when it is printing the ASM. It turns out that the new code path taken due to
legalizing a scalar_to_vector of i64 -> v2i64 exposes a missing check in a
micro optimization to change a load followed by a scalar_to_vector into a
load and splat instruction on PPC.

llvm-svn: 251798
2015-11-02 14:01:11 +00:00
Nemanja Ivanovic d389657399 Vector element extraction without stack operations on Power 8
This patch corresponds to review:
http://reviews.llvm.org/D12032

This patch builds onto the patch that provided scalar to vector conversions
without stack operations (D11471).
Included in this patch:

    - Vector element extraction for all vector types with constant element number
    - Vector element extraction for v16i8 and v8i16 with variable element number
    - Removal of some unnecessary COPY_TO_REGCLASS operations that ended up
      unnecessarily moving things around between registers

Not included in this patch (will be in upcoming patch):

    - Vector element extraction for v4i32, v4f32, v2i64 and v2f64 with
      variable element number
    - Vector element insertion for variable/constant element number

Testing is provided for all extractions. The extractions that are not
implemented yet are just placeholders.

llvm-svn: 249822
2015-10-09 11:12:18 +00:00
Nemanja Ivanovic 5f1cea4141 Temporary fix for the self-host failures introduced by rL244921.
This revision has introduced an issue that only affects bootstrapped compiler
when it is printing the ASM. I am working on resolving the issue, but in the
meantime, I'm disabling the legalization of scalar_to_vector operation for v2i64
and the associated testing until I can get this fixed.

llvm-svn: 245481
2015-08-19 19:04:47 +00:00
Nemanja Ivanovic 1c39ca6501 Scalar to vector conversions using direct moves
This patch corresponds to review:
http://reviews.llvm.org/D11471

It improves the code generated for converting a scalar to a vector value. With
direct moves from GPRs to VSRs, we no longer require expensive stack operations
for this. Subsequent patches will handle the reverse case and more general
operations between vectors and their scalar elements.

llvm-svn: 244921
2015-08-13 17:40:44 +00:00