Commit Graph

5 Commits

Author SHA1 Message Date
Quentin Colombet
c91f34ae54 [X86] Do not custom lower UINT_TO_FP when the target type does not
match the custom lowering.

<rdar://problem/19026326>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222489 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-21 00:47:19 +00:00
Quentin Colombet
8201185d61 [X86] Custom lower UINT_TO_FP from v4f32 to v4i32, and for v8f32 to v8i32 if
AVX2 is available.
According to IACA, the new lowering has a throughput of 8 cycles instead of 13
with the previous one.

Althought this lowering kicks in some SPECs benchmarks, the performance
improvement was within the noise.

Correctness testing has been done for the whole range of uint32_t with the
following program:
    uint4 v = (uint4) {0,1,2,3};
    uint32_t i;
    
    //Check correctness over entire range for uint4 -> float4 conversion
    for( i = 0; i < 1U << (32-2); i++ )
    {
        float4 t = test(v);
        float4 c = correct(v);
        
        if( 0xf != _mm_movemask_ps( t == c ))
        {
            printf( "Error @ %vx: %vf vs. %vf\n", v, c, t);
            return -1;
        }
        
        v += 4;
    }
Where "correct" is the old lowering and "test" the new one.

The patch adds a test case for the two custom lowering instruction.
It also modifies the vector cost model, which is why cast.ll and uitofp.ll are
modified.
2009-02-26-MachineLICMBug.ll is also modified because we now hoist 7
instructions instead of 4 (3 more constant loads).

rdar://problem/18153096>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221657 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 02:23:47 +00:00
Stephen Lin
b4dc0233c9 Convert CodeGen/*/*.ll tests to use the new CHECK-LABEL for easier debugging. No functionality change and all tests pass after conversion.
This was done with the following sed invocation to catch label lines demarking function boundaries:
    sed -i '' "s/^;\( *\)\([A-Z0-9_]*\):\( *\)test\([A-Za-z0-9_-]*\):\( *\)$/;\1\2-LABEL:\3test\4:\5/g" test/CodeGen/*/*.ll
which was written conservatively to avoid false positives rather than false negatives. I scanned through all the changes and everything looks correct.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186258 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-13 20:38:47 +00:00
Benjamin Kramer
eb274e6bdd Rename the "sandybridge" subtarget to "corei7-avx", for GCC compatibility.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131730 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-20 15:11:26 +00:00
Nadav Rotem
06cc324b9d Add support for legalizing UINT_TO_FP of vectors on platforms which do
not have native support for this operation (such as X86).
The legalized code uses two vector INT_TO_FP operations and is faster
than scalarizing.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127951 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-19 13:09:10 +00:00