For stack frames requiring realignment, three pointers may be needed:
- ebp to address incoming arguments
- esi (could be any callee-saved register) to address locals
- esp to address outgoing arguments
We would use esi unconditionally without verifying that it did not
conflict with inline assembly.
This change doesn't do the verification, it simply emits a fatal error
on functions that use stack realignment, dynamic SP adjustments, and
inline assembly.
Because stack realignment is common on Windows, we also no longer assume
that MS inline assembly clobbers esp. Instead, we analyze the inline
instructions for implicit definitions and check if esp is there. If so,
we require the use of a base pointer and consider it in the condition
above.
Mostly fixes PR16830, but we could try harder to find a non-conflicting
base pointer.
Reviewers: sunfish
Differential Revision: http://llvm-reviews.chandlerc.com/D1317
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196876 91177308-0d34-0410-b5e6-96231b3b80d8
This patch tries to avoid unrelated changes other than fixing a few
hyphen-related ambiguities and contractions in nearby lines.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196471 91177308-0d34-0410-b5e6-96231b3b80d8
given
declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i32, i1)
declare void @foo()
define void @bar() {
call void @foo()
call void @llvm.memset.p0i8.i32(i8* null, i8 0, i32 188, i32 1, i1 false)
ret void
}
We used to produce
L_foo$stub:
.indirect_symbol _foo
.ascii "\364\364\364\364\364"
_memset$stub:
.indirect_symbol _memset
.ascii "\364\364\364\364\364"
We not produce a private stub for memset too.
Stubs are not needed with recent linkers, but we still produce them for darwin8.
Thanks to David Fang for confirming that gcc used to do this too.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196468 91177308-0d34-0410-b5e6-96231b3b80d8
Unlike msvc, when handling a thiscall + sret gcc will
* Put the sret in %ecx
* Put the this pointer is (%esp)
This fixes, for example, calling stringstream::str.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196312 91177308-0d34-0410-b5e6-96231b3b80d8
- The fix to PR17631 fixes part of the cases where 'vzeroupper' should
not be issued before 'call' insn. There're other cases where helper
calls will be inserted not limited to epilog. These helper calls do
not follow the standard calling convention and won't clobber any YMM
registers. (So far, all call conventions will clobber any or part of
YMM registers.)
This patch enhances the previous fix to cover more cases 'vzerosupper' should
not be inserted by checking if that function call won't clobber any YMM
registers and skipping it if so.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196261 91177308-0d34-0410-b5e6-96231b3b80d8
It is only used for asm printing.
On X86 we put basic block addresses on register before passing them to inline
asm, so the MO_MachineBasicBlock case was dead.
MO_ExternalSymbol was dead since any symbol being passed to inline asm
is represented as MO_GlobalAddress.
The MO_GlobalAddress and MO_Register cases were not tested.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195824 91177308-0d34-0410-b5e6-96231b3b80d8
- Fix bug in (vsext (vzext x)) -> (vsext x) in SIGN_EXTEND_IN_REG
lowering where we need to check whether x is a vector type (in-reg
type) of i8, i16 or i32; otherwise, that optimization is not valid.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195779 91177308-0d34-0410-b5e6-96231b3b80d8
A Direct stack map location records the address of frame index. This
address is itself the value that the runtime requested. This differs
from IndirectMemRefOp locations, which refer to a stack locations from
which the requested values must be loaded. Direct locations can
directly communicate the address if an alloca, while IndirectMemRefOp
handle register spills.
For example:
entry:
%a = alloca i64...
llvm.experimental.stackmap(i32 <ID>, i32 <shadowBytes>, i64* %a)
Since both the alloca and stackmap intrinsic are in the entry block,
and the intrinsic takes the address of the alloca, the runtime can
assume that LLVM will not substitute alloca with any intervening
value. This must be verified by the runtime by checking that the stack
map's location is a Direct location type. The runtime can then
determine the alloca's relative location on the stack immediately after
compilation, or at any time thereafter. This differs from Register and
Indirect locations, because the runtime can only read the values in
those locations when execution reaches the instruction address of the
stack map.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195712 91177308-0d34-0410-b5e6-96231b3b80d8
We are going to drop debug info without a version number or with a different
version number, to make sure we don't crash when we see bitcode files with
different debug info metadata format.
Make tests more robust by removing hard-coded metadata numbers in CHECK lines.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195535 91177308-0d34-0410-b5e6-96231b3b80d8
We are going to drop debug info without a version number or with a different
version number, to make sure we don't crash when we see bitcode files with
different debug info metadata format.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195504 91177308-0d34-0410-b5e6-96231b3b80d8
Utilizing the 8 and 16 bit comparison instructions, even when an input can
be folded into the comparison instruction itself, is typically not worth it.
There are too many partial register stalls as a result, leading to significant
slowdowns. By always performing comparisons on at least 32-bit
registers, performance of the calculation chain leading to the
comparison improves. Continue to use the smaller comparisons when
minimizing size, as that allows better folding of loads into the
comparison instructions.
rdar://15386341
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195496 91177308-0d34-0410-b5e6-96231b3b80d8
Improvements over r195317:
- Set/restore EnableFastISel flag instead of just running FastISel within
SelectAllBasicBlocks; the flag is checked in various places, and
FastISel won't run properly if those places don't do the right thing.
- Test looks for normal ISel versus FastISel behavior, and not
something more subtle that doesn't work everywhere.
Based on work by Andrea Di Biagio.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195491 91177308-0d34-0410-b5e6-96231b3b80d8
- When simplifying the mask generation for BLEND, check whether that mask is
also consumed by other non-BLEND insns. If true, skip that simplification.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195476 91177308-0d34-0410-b5e6-96231b3b80d8
AMD's processors family K7, K8, K10, K12, K15 and K16 are known to have SHLD/SHRD instructions with very poor latency. Optimization guides for these processors recommend using an alternative sequence of instructions. For these AMD's processors, I disabled folding (or (x << c) | (y >> (64 - c))) when we are not optimizing for size.
It might be beneficial to disable this folding for some of the Intel's processors. However, since I couldn't find specific recommendations regarding using SHLD/SHRD instructions on Intel's processors, I haven't disabled this peephole for Intel.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195383 91177308-0d34-0410-b5e6-96231b3b80d8
clang optimizes tail calls, as in this example:
int foo(void);
int bar(void) {
return foo();
}
where the call is transformed to:
calll .L0$pb
.L0$pb:
popl %eax
.Ltmp0:
addl $_GLOBAL_OFFSET_TABLE_+(.Ltmp0-.L0$pb), %eax
movl foo@GOT(%eax), %eax
popl %ebp
jmpl *%eax # TAILCALL
However, the GOT references must all be resolved at dlopen() time, and so this
approach cannot be used with lazy dynamic linking (e.g. using RTLD_LAZY), which
usually populates the PLT with stubs that perform the actual resolving.
This patch changes X86TargetLowering::LowerCall() to skip tail call
optimization, if the called function is a global or external symbol.
Patch by Dimitry Andric!
PR15086
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195318 91177308-0d34-0410-b5e6-96231b3b80d8
We now only allow breaking source order if the exit block frequency is
significantly higher than the other exit block. The actual bias is
currently under a flag so the best cut-off can be found; the flag
defaults to the old behavior. The idea is to get some benchmark coverage
over different values for the flag and pick the best one.
When we require the new frequency to be at least 20% higher than the old
frequency I see a 5% speedup on zlib's deflate when compressing a random
file on x86_64/westmere. Hal reported a small speedup on Fhourstones on
a BG/Q and no regressions in the test suite.
The test case is the full long_match function from zlib's deflate. I was
reluctant to add it for previous tweaks to branch probabilities because
it's large and potentially fragile, but changed my mind since it's an
important use case and more likely to break with all the current work
going into the PGO infrastructure.
Differential Revision: http://llvm-reviews.chandlerc.com/D2202
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195265 91177308-0d34-0410-b5e6-96231b3b80d8
Implementing this on bigendian platforms could get strange. I added a
target hook, getStackSlotRange, per Jakob's recommendation to make
this as explicit as possible.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194942 91177308-0d34-0410-b5e6-96231b3b80d8
Stop folding constant adds into GEP when the type size doesn't match.
Otherwise, the adds' operands are effectively being promoted, changing the
conditions of an overflow. Results are different when:
sext(a) + sext(b) != sext(a + b)
Problem originally found on x86-64, but also fixed issues with ARM and PPC,
which used similar code.
<rdar://problem/15292280>
Patch by Duncan Exon Smith!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194840 91177308-0d34-0410-b5e6-96231b3b80d8