Patch by Mikulas Patocka. I added the test. I checked that for cpu names that
gas knows about, it also doesn't generate nopl.
The modified cpus:
i686 - there are i686-class CPUs that don't have nopl: Via c3, Transmeta
Crusoe, Microsoft VirtualBox - see
https://bbs.archlinux.org/viewtopic.php?pid=775414
k6, k6-2, k6-3, winchip-c6, winchip2 - these are 586-class CPUs
via c3 c3-2 - see https://bugs.archlinux.org/task/19733 as a proof that
Via c3 and c3-Nehemiah don't have nopl
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195679 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
- 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
Hard-coded operand indices were scattered throughout lowering stages
and layers. It was super bug prone.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195093 91177308-0d34-0410-b5e6-96231b3b80d8
This patch removes most of the trivial cases of weak vtables by pinning them to
a single object file. The memory leaks in this version have been fixed. Thanks
Alexey for pointing them out.
Differential Revision: http://llvm-reviews.chandlerc.com/D2068
Reviewed by Andy
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195064 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r190888, to fix PR17967. The original change wasn't
the right way to get @feat.00 into the object file. The right fix is to
make @feat.00 be a global symbol.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195053 91177308-0d34-0410-b5e6-96231b3b80d8
This change is incorrect. If you delete virtual destructor of both a base class
and a subclass, then the following code:
Base *foo = new Child();
delete foo;
will not cause the destructor for members of Child class. As a result, I observe
plently of memory leaks. Notable examples I investigated are:
ObjectBuffer and ObjectBufferStream, AttributeImpl and StringSAttributeImpl.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194997 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
If a null call target is provided, don't emit a dummy call. This
allows the runtime to reserve as little nop space as it needs without
the requirement of emitting a call.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194676 91177308-0d34-0410-b5e6-96231b3b80d8
This patch reapplies r193676 with an additional fix for the Hexagon backend. The
SystemZ backend has already been fixed by r194148.
The Type Legalizer recognizes that VSELECT needs to be split, because the type
is to wide for the given target. The same does not always apply to SETCC,
because less space is required to encode the result of a comparison. As a result
VSELECT is split and SETCC is unrolled into scalar comparisons.
This commit fixes the issue by checking for VSELECT-SETCC patterns in the DAG
Combiner. If a matching pattern is found, then the result mask of SETCC is
promoted to the expected vector mask type for the given target. Now the type
legalizer will split both VSELECT and SETCC.
This allows the following X86 DAG Combine code to sucessfully detect the MIN/MAX
pattern. This fixes PR16695, PR17002, and <rdar://problem/14594431>.
Reviewed by Nadav
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194542 91177308-0d34-0410-b5e6-96231b3b80d8
We already know how to fold a reload from a frameindex without
analyzing the load instruction. Generalize this to handle any
frameindex load. This streamlines the logic for rematerializing loads
from stack arguments. As a side effect, it allows stackmaps to record
a stack argument location without spilling it.
Verified no effect on codegen for llvm test-suite.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194497 91177308-0d34-0410-b5e6-96231b3b80d8
X86AsmPrinter::EmitInstruction, rather than X86MCInstLower::Lower.
The aim is to improve the reusability of the X86MCInstLower class by making it
more function-like. The X86::MORESTACK_RET_RESTORE_R10 pseudo broke the
function model by emitting an extra instruction to the MCStreamer attached to
the AsmPrinter.
The patch should have no impact on generated code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194431 91177308-0d34-0410-b5e6-96231b3b80d8
Fixes <rdar://15432754> [JS] Assertion: "Folded a def to a non-store!"
The primary purpose of anyregcc is to prevent a patchpoint's call
arguments and return value from being spilled. They must be available
in a register, although the calling convention does not pin the
register. It's up to the front end to avoid using this convention for
calls with more arguments than allocatable registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194428 91177308-0d34-0410-b5e6-96231b3b80d8
This patch moves the jump address materialization inside the noop slide. This
enables patching of the materialization itself or its complete removal. This
patch also adds the ability to define scratch registers that can be used safely
by the code called from the patchpoint intrinsic. At least one scratch register
is required, because that one is used for the materialization of the jump
address. This patch depends on D2009.
Differential Revision: http://llvm-reviews.chandlerc.com/D2074
Reviewed by Andy
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194306 91177308-0d34-0410-b5e6-96231b3b80d8
The idea of the AnyReg Calling Convention is to provide the call arguments in
registers, but not to force them to be placed in a paticular order into a
specified set of registers. Instead it is up tp the register allocator to assign
any register as it sees fit. The same applies to the return value (if
applicable).
Differential Revision: http://llvm-reviews.chandlerc.com/D2009
Reviewed by Andy
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194293 91177308-0d34-0410-b5e6-96231b3b80d8
On darwin, when trying to create compact unwind info, a .cfi_cfa_def
directive would case an llvm_unreachable() to be hit. Back off when we
see this directive and generate the regular DWARF style eh_frame.
rdar://15406518
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194285 91177308-0d34-0410-b5e6-96231b3b80d8
- When selecting BLEND from vselect, the operands need swapping as due to the
difference between vselect and SSE/AVX's BLEND insn
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193900 91177308-0d34-0410-b5e6-96231b3b80d8
