Commit Graph

6 Commits

Author SHA1 Message Date
Tom Stellard cb6ba62d6f AMDGPU/SI: Enable the post-ra scheduler
Summary:
This includes a hazard recognizer implementation to replace some of
the hazard handling we had during frame index elimination.

Reviewers: arsenm

Subscribers: qcolombet, arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D18602

llvm-svn: 268143
2016-04-30 00:23:06 +00:00
Tom Stellard 0bc954e3bc AMDGPU/SI: Enable lanemask tracking in misched
Summary:
This results in higher register usage, but should make it easier for
the compiler to hide latency.

This pass is a prerequisite for some more scheduler improvements, and I
think the increase register usage with this patch is acceptable, because
when combined with the scheduler improvements, the total register usage
will decrease.

shader-db stats:

2382 shaders in 478 tests
Totals:
SGPRS: 48672 -> 49088 (0.85 %)
VGPRS: 34148 -> 34847 (2.05 %)
Code Size: 1285816 -> 1289128 (0.26 %) bytes
LDS: 28 -> 28 (0.00 %) blocks
Scratch: 492544 -> 573440 (16.42 %) bytes per wave
Max Waves: 6856 -> 6846 (-0.15 %)
Wait states: 0 -> 0 (0.00 %)

Depends on D18451

Reviewers: nhaehnle, arsenm

Subscribers: arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D18452

llvm-svn: 264876
2016-03-30 16:35:09 +00:00
Tom Stellard 2e045bbc5f AMDGPU/SI: Prevent the DAGCombiner from creating setcc with i1 inputs
Reviewers: arsenm

Subscribers: arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D15035

llvm-svn: 258256
2016-01-20 00:13:22 +00:00
Tom Stellard 05691a678e DAGCombiner: Check shouldReduceLoadWidth before combining (and (load), x) -> extload
Reviewers: resistor, arsenm

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13805

llvm-svn: 252349
2015-11-06 21:58:37 +00:00
Tom Stellard bd8a0856e2 AMDGPU/SI: Better handle s_wait insertion
We can wait on either VM, EXP or LGKM.
The waits are independent.

Without this patch, a wait inserted because of one of them
would also wait for all the previous others.
This patch makes s_wait only wait for the ones we need for the next
instruction.

Here's an example of subtle perf reduction this patch solves:

This is without the patch:

buffer_load_format_xyzw v[8:11], v0, s[44:47], 0 idxen
buffer_load_format_xyzw v[12:15], v0, s[48:51], 0 idxen
s_load_dwordx4 s[44:47], s[8:9], 0xc
s_waitcnt lgkmcnt(0)
buffer_load_format_xyzw v[16:19], v0, s[52:55], 0 idxen
s_load_dwordx4 s[48:51], s[8:9], 0x10
s_waitcnt vmcnt(1)
buffer_load_format_xyzw v[20:23], v0, s[44:47], 0 idxen

The s_waitcnt vmcnt(1) is useless.
The reason it is added is because the last
buffer_load_format_xyzw needs s[44:47], which was issued
by the first s_load_dwordx4. It waits for all VM
before that call to have finished.

Internally after every instruction, 3 counters (for VM, EXP and LGTM)
are updated after every instruction. For example buffer_load_format_xyzw
will
increase the VM counter, and s_load_dwordx4 the LGKM one.

Without the patch, for every defined register,
the current 3 counters are stored, and are used to know
how long to wait when an instruction needs the register.

Because of that, the s[44:47] counter includes that to use the register
you need to wait for the previous buffer_load_format_xyzw.

Instead this patch stores only the counters that matter for the
register,
and puts zero for the other ones, since we don't need any wait for them.

Patch by: Axel Davy

Differential Revision: http://reviews.llvm.org/D11883

llvm-svn: 245755
2015-08-21 22:47:27 +00:00
Tom Stellard 45bb48ea19 R600 -> AMDGPU rename
llvm-svn: 239657
2015-06-13 03:28:10 +00:00