Commit Graph

8 Commits

Author SHA1 Message Date
Artem Belevich b2e76a5e7a [NVPTX] Improve lowering of byval args of device functions.
Avoid unnecessary spills of byval arguments of device functions to
local space on SASS level and subsequent pointer conversion to generic
address space that follows. Instead, make a local copy in IR, provide
a way to access arguments directly, and let LLVM optimize the copy away
when possible.

Differential Review: https://reviews.llvm.org/D21421

llvm-svn: 276153
2016-07-20 18:39:47 +00:00
Artem Belevich 4d5d7be8cc Revert r273313 "[NVPTX] Improve lowering of byval args of device functions."
The change causes llvm crash in some unoptimized builds.

llvm-svn: 274163
2016-06-29 20:51:15 +00:00
Artem Belevich d7ebcfb291 [NVPTX] Improve lowering of byval args of device functions.
Avoid unnecessary spills of such vars to local space on SASS level and
pointer space conversion.

Instead, make a local copy with appropriate addrspacecasts and let
LLVM optimize them away when possible.

This allows loading value of the argument using [symbol+offset]
instead of converting argument to general space pointer and using it
for indexing (which also implicitly converts param space pointer to
local space one on SASS level and triggers copying of argument into
local space in the process).

This reduces call overhead, uses less registers and reduces overall
SASS size by 2-4%.

Differential Review: http://reviews.llvm.org/D21421

llvm-svn: 273313
2016-06-21 20:30:26 +00:00
Jingyue Wu cf70053b20 [NVPTX] convert pointers in byval kernel arguments to global
Summary:
For example, in

  struct S {
    int *x;
    int *y;
  };
  __global__ void foo(S s) {
    int *b = s.y;
    // use b
  }

"b" is guaranteed to point to global. NVPTX should emit ld.global/st.global for
accessing "b".

Reviewers: jholewinski

Subscribers: llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D11505

llvm-svn: 243790
2015-07-31 21:44:14 +00:00
Jingyue Wu 3203818bf7 [NVPTX] noop when kernel pointers are already global
Summary:
Some front ends make kernel pointers global already. In that case,
handlePointerParams does nothing.

Test Plan: more tests in lower-kernel-ptr-arg.ll

Reviewers: grosser

Subscribers: jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D10779

llvm-svn: 240849
2015-06-26 22:35:43 +00:00
Jingyue Wu a2f6027a31 [NVPTX] roll forward r239082
NVPTXISelDAGToDAG translates "addrspacecast to param" to
NVPTX::nvvm_ptr_gen_to_param

Added an llc test in bug21465.

llvm-svn: 239100
2015-06-04 21:28:26 +00:00
Jingyue Wu b8f38668d5 Revert r239082
llc crashed for NVPTX backend

llvm-svn: 239094
2015-06-04 21:07:08 +00:00
Jingyue Wu f3a8079b75 [NVPTX] kernel pointer arguments point to the global address space
Summary:
With this patch, NVPTXLowerKernelArgs converts a kernel pointer argument to a
pointer in the global address space. This change, along with
NVPTXFavorNonGenericAddrSpaces, allows the NVPTX backend to emit ld.global.*
and st.global.* for accessing kernel pointer arguments.

Minor changes:
1. refactor: extract function convertToPointerInAddrSpace
2. fix a bug in the test case in bug21465.ll

Test Plan: lower-kernel-ptr-arg.ll

Reviewers: eliben, meheff, jholewinski

Reviewed By: jholewinski

Subscribers: wengxt, jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D10154

llvm-svn: 239082
2015-06-04 20:19:38 +00:00