Commit Graph

2 Commits

Author SHA1 Message Date
Ehsan Amiri a538b0f023 Adding -verify-machineinstrs option to PowerPC tests
Currently we have a number of tests that fail with -verify-machineinstrs.
To detect this cases earlier we add the option to the testcases with the
exception of tests that will currently fail with this option. PR 27456 keeps
track of this failures.

No code review, as discussed with Hal Finkel.

llvm-svn: 277624
2016-08-03 18:17:35 +00:00
Hal Finkel 851b33a0b1 [PowerPC] Load two floats directly instead of using one 64-bit integer load
When dealing with complex<float>, and similar structures with two
single-precision floating-point numbers, especially when such things are being
passed around by value, we'll sometimes end up loading both float values by
extracting them from one 64-bit integer load. It looks like this:

  t13: i64,ch = load<LD8[%ref.tmp]> t0, t6, undef:i64
      t16: i64 = srl t13, Constant:i32<32>
    t17: i32 = truncate t16
  t18: f32 = bitcast t17
    t19: i32 = truncate t13
  t20: f32 = bitcast t19

The problem, especially before the P8 where those bitcasts aren't legal (and
get expanded via the stack), is that it would have been better to use two
floating-point loads directly. Here we add a target-specific DAGCombine to do
just that. In short, we turn:

	ld 3, 0(5)
	stw 3, -8(1)
	rldicl 3, 3, 32, 32
	stw 3, -4(1)
	lfs 3, -4(1)
	lfs 0, -8(1)

into:

        lfs 3, 4(5)
        lfs 0, 0(5)

llvm-svn: 264988
2016-03-31 02:56:05 +00:00