Commit Graph

5 Commits

Author SHA1 Message Date
Simon Pilgrim d862e0f33a [X86][SSE][CostModel] Added full set of sitofp/uitofp costings for SSE2/AVX/AVX2/AVX512F.
Merged separate (but equivalent) SSE2/AVX512F tests.

Removed codegen tests since these are already done better in test/CodeGen/X86.

The actual cost values still need to be updated to match recent codegen improvements.

llvm-svn: 240219
2015-06-20 14:58:01 +00:00
Simon Pilgrim de94fa6438 [X86][SSE][CostModel] Fixed uitofp/sitofp cost target tests to specify sse2/avx2/avx512f directly instead of via a cpu model.
llvm-svn: 240062
2015-06-18 21:26:01 +00:00
Quentin Colombet 360460ba64 [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>

llvm-svn: 221657
2014-11-11 02:23:47 +00:00
Arnold Schwaighofer c0c7ff4ac0 X86 cost model: Exit before calling getSimpleVT on non-simple VTs
getSimpleVT can only handle simple value types.

radar://13676022

llvm-svn: 179714
2013-04-17 20:04:53 +00:00
Arnold Schwaighofer f47d2d7f6b X86 cost model: Model cost for uitofp and sitofp on SSE2
The costs are overfitted so that I can still use the legalization factor.

For example the following kernel has about half the throughput vectorized than
unvectorized when compiled with SSE2. Before this patch we would vectorize it.

unsigned short A[1024];
double B[1024];
void f() {
  int i;
  for (i = 0; i < 1024; ++i) {
    B[i] = (double) A[i];
  }
}

radar://13599001

llvm-svn: 179033
2013-04-08 18:05:48 +00:00