Commit Graph

5 Commits

Author SHA1 Message Date
Simon Dardis 1dcb911061 [mips] Restrict tail call optimization
The tail call optimization was being used without proper consideration of
ABI requirements for saving and restoring the GP. This patch restricts tail
call optimization to functions within the same translation unit.

Reviewers: vkalintiris

Differential Revision: https://reviews.llvm.org/D24763

llvm-svn: 287505
2016-11-20 21:23:08 +00:00
Simon Dardis d2ed8abb15 [mips] Disable tail calls temporarily
Disable tail calls while the remaining bugs are fixed. Enable only for tests.

Reviewers: vkalintiris

Differential Review: https://reviews.llvm.org/D24912

llvm-svn: 282487
2016-09-27 13:15:54 +00:00
Simon Dardis 57f4ae4625 [mips] Enable tail calls by default
Enable tail calls by default for (micro)MIPS(64).

microMIPS is slightly more tricky than doing it for MIPS(R6) or microMIPSR6.
microMIPS has two instruction encodings: 16bit and 32bit along with some
restrictions on the size of the instruction that can fill the delay slot.
For safe tail calls for microMIPS, the delay slot filler attempts to find
a correct size instruction for the delay slot of TAILCALL pseudos.

Reviewers: dsanders, vkalintris

Subscribers: jfb, dsanders, sdardis, llvm-commits

Differential Revision: https://reviews.llvm.org/D21138

llvm-svn: 277708
2016-08-04 09:17:07 +00:00
Petar Jovanovic e578e970cb [mips] Make Static a default relocation model for MIPS codegen
This change follows up defaults for GCC and Clang, so LLVM does not differ
from them. While number of the test files are touched with this change, they
all keep the old (expected) behaviour with the explicit option:
"-relocation-model=pic"
The tests that have not been touched are insensitive to relocation model.

Differential Revision: http://reviews.llvm.org/D17995

llvm-svn: 265949
2016-04-11 15:24:23 +00:00
Akira Hatanaka af4211ad94 [mips] Make sure loads from lazy-binding entries do not get CSE'd or hoisted out
of loops.

Previously, two consecutive calls to function "func" would result in the
following sequence of instructions:

1. load $16, %got(func)($gp) // load address of lazy-binding stub.
2. move $25, $16
3. jalr $25                  // jump to lazy-binding stub.
4. nop
5. move $25, $16
6. jalr $25                  // jump to lazy-binding stub again.

With this patch, the second call directly jumps to func's address, bypassing
the lazy-binding resolution routine:

1. load $25, %got(func)($gp) // load address of lazy-binding stub.
2. jalr $25                  // jump to lazy-binding stub.
3. nop
4. load $25, %got(func)($gp) // load resolved address of func.
5. jalr $25                  // directly jump to func.

llvm-svn: 191591
2013-09-28 00:12:32 +00:00