Summary:
This patch skips DAG combine of fp_round (fp_round x) if it results in
an fp_round from f80 to f16.
fp_round from f80 to f16 always generates an expensive (and as yet,
unimplemented) libcall to __truncxfhf2. This prevents selection of
native f16 conversion instructions from f32 or f64. Moreover, the first
(value-preserving) fp_round from f80 to either f32 or f64 may become a
NOP in platforms like x86.
Reviewers: ab
Subscribers: srhines, llvm-commits
Differential Revision: http://reviews.llvm.org/D17221
llvm-svn: 260769
Officially, we don't acknowledge non-default configurations of MXCSR,
as getting there would require usage of the FENV_ACCESS pragma (at
least insofar as rounding mode is concerned).
We don't support the pragma, so we can assume that the default
rounding mode - round to nearest, ties to even - is always used.
However, it's inconsistent with the rest of the instruction set,
where MXCSR is always effective (unless otherwise specified).
Also, it's an unnecessary obstacle to the few brave souls that use
fenv.h with LLVM.
Avoid the hard-coded rounding mode for fp_to_f16; use MXCSR instead.
llvm-svn: 259448
Caller saved regs differ between SysV and Win64. Use the tail call available set to scavenge from.
Refactor register info to create new helper to get at tail call GPRs. Added a new test case for windows. Fixed up a number of X64 tests since now RCX is preferred over RDX on SysV.
Differential Revision: http://reviews.llvm.org/D14878
llvm-svn: 253927
Summary:
r235215 adds support for f16 to be considered as a load/store type and
promote f16 operations to f32.
This patch has miscellaneous fixes for the X86 backend so all f16
operations are handled:
1. Set loadextaction for f16 vectors to expand.
2. Handle FP_EXTEND in a switch statement when handling v2f32
3. Do not fold (FP_TO_SINT (load f16)) into FP_TO_INT*_IN_MEM or
(store (SINT_TO_FP )) to a FILD.
Tests included.
Reviewers: ab, srhines, delena
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9092
llvm-svn: 237004
Essentially the same as the GEP change in r230786.
A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)
import fileinput
import sys
import re
pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")
for line in sys.stdin:
sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))
Reviewers: rafael, dexonsmith, grosser
Differential Revision: http://reviews.llvm.org/D7649
llvm-svn: 230794
Actual support for softening f16 operations is still limited, and can be added
when it's needed. But Soften is much closer to being a useful thing to try
than keeping it Legal when no registers can actually hold such values.
Longer term, we probably want something between Soften and Promote semantics
for most targets, it'll be more efficient to promote the 4 basic operations to
f32 than libcall them.
llvm-svn: 213372
Kevin B. Smith