Commit Graph

3 Commits

Author SHA1 Message Date
Craig Topper ad140cfb68 [X86] Add comment string for broadcast loads from the constant pool.
Summary:
When broadcasting from the constant pool its useful to print out the final vector similar to what we do for normal moves from the constant pool.

I changed only a couple tests that were broadcast focused. One of them had been previously hand tweaked after running the script so that it could check the constant pool declaration. But I think this patch makes that unnecessary now since we can check the comment instead.

Reviewers: spatel, RKSimon, zvi

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34923

llvm-svn: 307062
2017-07-04 05:46:11 +00:00
Ahmed Bougacha 018a68f9e4 [X86] Correctly broadcast NaN-like integers as float on AVX.
Since r288804, we try to lower build_vectors on AVX using broadcasts of
float/double.  However, when we broadcast integer values that happen to
have a NaN float bitpattern, we lose the NaN payload, thereby changing
the integer value being broadcast.

This is caused by ConstantFP::get, to which we pass the splat i32 as
a float (by bitcasting it using bitsToFloat).  ConstantFP::get takes
a double parameter, so we end up lossily converting a single-precision
NaN to double-precision.

Instead, avoid any kinds of conversions by directly building an APFloat
from the splatted APInt.

Note that this also fixes another piece of code (broadcast of
subvectors), that currently isn't susceptible to the same problem.

Also note that we could really just use APInt and ConstantInt
throughout: the constant pool type doesn't matter much.  Still, for
consistency, use the appropriate type.

llvm-svn: 304590
2017-06-02 20:02:59 +00:00
Ayman Musa 86c00b799f [X86][AVX512] Detect repeated constant patterns in BUILD_VECTOR suitable for broadcasting.
Check if a build_vector node includes a repeated constant pattern and replace it with a broadcast of that pattern.
For example:
"build_vector <0, 1, 2, 3, 0, 1, 2, 3>" would be replaced by "broadcast <0, 1, 2, 3>"

Differential Revision: https://reviews.llvm.org/D26802

llvm-svn: 288804
2016-12-06 12:24:14 +00:00