Summary:
No need to have this per-architecture. While there, unify 32-bit ARM's
behaviour with what changed elsewhere and start function names lowercase
as per the coding standards. Individual entry emission code goes to the
entry's own class.
Fully tested on amd64, cross-builds on both ARMs and PowerPC.
Reviewers: dberris
Subscribers: aemerson, llvm-commits
Differential Revision: https://reviews.llvm.org/D28209
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290858 91177308-0d34-0410-b5e6-96231b3b80d8
This implements execute-only support for ARM code generation, which
prevents the compiler from generating data accesses to code sections.
The following changes are involved:
* Add the CodeGen option "-arm-execute-only" to the ARM code generator.
* Add the clang flag "-mexecute-only" as well as the GCC-compatible
alias "-mpure-code" to enable this option.
* When enabled, literal pools are replaced with MOVW/MOVT instructions,
with VMOV used in addition for floating-point literals. As the MOVT
instruction is required, execute-only support is only available in
Thumb mode for targets supporting ARMv8-M baseline or Thumb2.
* Jump tables are placed in data sections when in execute-only mode.
* The execute-only text section is assigned section ID 0, and is
marked as unreadable with the SHF_ARM_PURECODE flag with symbol 'y'.
This also overrides selection of ELF sections for globals.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289784 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds simplified support for tail calls on ARM with XRay instrumentation.
Known issue: compiled with generic flags: `-O3 -g -fxray-instrument -Wall
-std=c++14 -ffunction-sections -fdata-sections` (this list doesn't include my
specific flags like --target=armv7-linux-gnueabihf etc.), the following program
#include <cstdio>
#include <cassert>
#include <xray/xray_interface.h>
[[clang::xray_always_instrument]] void __attribute__ ((noinline)) fC() {
std::printf("In fC()\n");
}
[[clang::xray_always_instrument]] void __attribute__ ((noinline)) fB() {
std::printf("In fB()\n");
fC();
}
[[clang::xray_always_instrument]] void __attribute__ ((noinline)) fA() {
std::printf("In fA()\n");
fB();
}
// Avoid infinite recursion in case the logging function is instrumented (so calls logging
// function again).
[[clang::xray_never_instrument]] void simplyPrint(int32_t functionId, XRayEntryType xret)
{
printf("XRay: functionId=%d type=%d.\n", int(functionId), int(xret));
}
int main(int argc, char* argv[]) {
__xray_set_handler(simplyPrint);
printf("Patching...\n");
__xray_patch();
fA();
printf("Unpatching...\n");
__xray_unpatch();
fA();
return 0;
}
gives the following output:
Patching...
XRay: functionId=3 type=0.
In fA()
XRay: functionId=3 type=1.
XRay: functionId=2 type=0.
In fB()
XRay: functionId=2 type=1.
XRay: functionId=1 type=0.
XRay: functionId=1 type=1.
In fC()
Unpatching...
In fA()
In fB()
In fC()
So for function fC() the exit sled seems to be called too much before function
exit: before printing In fC().
Debugging shows that the above happens because printf from fC is also called as
a tail call. So first the exit sled of fC is executed, and only then printf is
jumped into. So it seems we can't do anything about this with the current
approach (i.e. within the simplification described in
https://reviews.llvm.org/D23988 ).
Differential Revision: https://reviews.llvm.org/D25030
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284456 91177308-0d34-0410-b5e6-96231b3b80d8
And associated commits, as they broke the Thumb bots.
This reverts commit r280935.
This reverts commit r280891.
This reverts commit r280888.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280967 91177308-0d34-0410-b5e6-96231b3b80d8
The R_ARM_PLT32 relocation is deprecated and is not produced by MC.
This means that the code being deleted is dead from the .o point of
view and was making the .s more confusing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272909 91177308-0d34-0410-b5e6-96231b3b80d8
Certain ARM instructions accept 32-bit immediate operands encoded as a 8-bit
integer value (0-255) and a 4-bit rotation (0-30, even). Current ARM assembly
syntax support in LLVM allows the decoded (32-bit) immediate to be specified
as a single immediate operand for such instructions:
mov r0, #4278190080
The ARMARM defines an extended assembly syntax allowing the encoding to be made
more explicit, as in:
mov r0, #255, #8 ; (same 32-bit value as above)
The behaviour of the two instructions can be different w.r.t flags, which is
documented under "Modified immediate constants" in ARMARM. This patch enables
support for this extended syntax at the MC layer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223113 91177308-0d34-0410-b5e6-96231b3b80d8
ARM symbol variants are written with parens instead of @ like this:
.word __GLOBAL_I_a(target1)
This commit adds support for parsing these symbol variants in
expressions. We introduce a new flag to MCAsmInfo that indicates the
parser should use parens to parse the symbol variant. The expression
parser is modified to look for symbol variants using parens instead
of @ when the corresponding MCAsmInfo flag is true.
The MCAsmInfo parens flag is enabled only for ARM on ELF.
By adding this flag to MCAsmInfo, we are able to get rid of
redundant ARM-specific symbol variants and use the generic variants
instead (e.g. VK_GOT instead of VK_ARM_GOT). We use the new
UseParensForSymbolVariant attribute in MCAsmInfo to correctly print
the symbol variants for arm.
To achive this we need to keep a handle to the MCAsmInfo in the
MCSymbolRefExpr class that we can check when printing the symbol
variant.
Updated Tests:
Changed case of symbol variant to match the generic kind.
test/CodeGen/ARM/tls-models.ll
test/CodeGen/ARM/tls1.ll
test/CodeGen/ARM/tls2.ll
test/CodeGen/Thumb2/tls1.ll
test/CodeGen/Thumb2/tls2.ll
PR18080
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196424 91177308-0d34-0410-b5e6-96231b3b80d8
These are handled almost identically to static mode (and ELF's global address
materialisation), except that a symbol may have "$non_lazy_ptr" appended. This
can be handled by passing appropriate flags along with the instruction instead
of using entirely separate pseudo-instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195655 91177308-0d34-0410-b5e6-96231b3b80d8
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.
There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.
The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.
I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).
I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171366 91177308-0d34-0410-b5e6-96231b3b80d8
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.
Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 91177308-0d34-0410-b5e6-96231b3b80d8
This is similar to implicit register operands. MC doesn't understand
register liveness and call clobbers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148437 91177308-0d34-0410-b5e6-96231b3b80d8
Eugene Zelenko
Dean Michael Berris
Prakhar Bahuguna
Stephan Bergmann
Kuba Mracek
Renato Golin
Etienne Bergeron
Aaron Ballman
Rafael Espindola
Jim Grosbach
Asiri Rathnayake
Saleem Abdulrasool
Craig Topper
David Peixotto
Tim Northover
Chandler Carruth
Jakob Stoklund Olesen