Commit Graph

3 Commits

Author SHA1 Message Date
Lei Huang 168d14b143 [PowerPC] Reduce register pressure by not materializing a constant just for use as an index register for X-Form loads/stores.
For this example:
float test (int *arr) {
    return arr[2];
}

We currently generate the following code:
  li r4, 8
  lxsiwax f0, r3, r4
  xscvsxdsp f1, f0

With this patch, we will now generate:
  addi r3, r3, 8
  lxsiwax f0, 0, r3
  xscvsxdsp f1, f0

Originally reported in: https://bugs.llvm.org/show_bug.cgi?id=27204
Differential Revision: https://reviews.llvm.org/D35027

llvm-svn: 307553
2017-07-10 16:44:45 +00:00
Nemanja Ivanovic 15748f4921 [PowerPC] Improvements for BUILD_VECTOR Vol. 4
This is the final patch in the series of patches that improves
BUILD_VECTOR handling on PowerPC. This adds a few peephole optimizations
to remove redundant instructions. It also adds a large test case which
encompasses a large set of code patterns that build vectors - this test
case was the motivator for this series of patches.

Differential Revision: https://reviews.llvm.org/D26066

llvm-svn: 288800
2016-12-06 11:47:14 +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