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630590abbc
[PowerPC] Replace foul hackery with real calls to __tls_get_addr My original support for the general dynamic and local dynamic TLS models contained some fairly obtuse hacks to generate calls to __tls_get_addr when lowering a TargetGlobalAddress. Rather than generating real calls, special GET_TLS_ADDR nodes were used to wrap the calls and only reveal them at assembly time. I attempted to provide correct parameter and return values by chaining CopyToReg and CopyFromReg nodes onto the GET_TLS_ADDR nodes, but this was also not fully correct. Problems were seen with two back-to-back stores to TLS variables, where the call sequences ended up overlapping with unhappy results. Additionally, since these weren't real calls, the proper register side effects of a call were not recorded, so clobbered values were kept live across the calls. The proper thing to do is to lower these into calls in the first place. This is relatively straightforward; see the changes to PPCTargetLowering::LowerGlobalTLSAddress() in PPCISelLowering.cpp. The changes here are standard call lowering, except that we need to track the fact that these calls will require a relocation. This is done by adding a machine operand flag of MO_TLSLD or MO_TLSGD to the TargetGlobalAddress operand that appears earlier in the sequence. The calls to LowerCallTo() eventually find their way to LowerCall_64SVR4() or LowerCall_32SVR4(), which call FinishCall(), which calls PrepareCall(). In PrepareCall(), we detect the calls to __tls_get_addr and immediately snag the TargetGlobalTLSAddress with the annotated relocation information. This becomes an extra operand on the call following the callee, which is expected for nodes of type tlscall. We change the call opcode to CALL_TLS for this case. Back in FinishCall(), we change it again to CALL_NOP_TLS for 64-bit only, since we require a TOC-restore nop following the call for the 64-bit ABIs. During selection, patterns in PPCInstrInfo.td and PPCInstr64Bit.td convert the CALL_TLS nodes into BL_TLS nodes, and convert the CALL_NOP_TLS nodes into BL8_NOP_TLS nodes. This replaces the code removed from PPCAsmPrinter.cpp, as the BL_TLS or BL8_NOP_TLS nodes can now be emitted normally using their patterns and the associated printTLSCall print method. Finally, as a result of these changes, all references to get-tls-addr in its various guises are no longer used, so they have been removed. There are existing TLS tests to verify the changes haven't messed anything up). I've added one new test that verifies that the problem with the original code has been fixed. This fixes a fatal "Bad machine code" error when compiling parts of libgomp for 32-bit PowerPC. |
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| cddl | ||
| contrib | ||
| crypto | ||
| etc | ||
| games | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| sys | ||
| tests | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| .arcconfig | ||
| .arclint | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| ObsoleteFiles.inc | ||
| README | ||
| UPDATING | ||
This is the top level of the FreeBSD source directory. This file was last revised on: $FreeBSD$ For copyright information, please see the file COPYRIGHT in this directory (additional copyright information also exists for some sources in this tree - please see the specific source directories for more information). The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree, the most commonly used one being ``world'', which rebuilds and installs everything in the FreeBSD system from the source tree except the kernel, the kernel-modules and the contents of /etc. The ``world'' target should only be used in cases where the source tree has not changed from the currently running version. See: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html for more information, including setting make(1) variables. The ``buildkernel'' and ``installkernel'' targets build and install the kernel and the modules (see below). Please see the top of the Makefile in this directory for more information on the standard build targets and compile-time flags. Building a kernel is a somewhat more involved process, documentation for which can be found at: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html And in the config(8) man page. Note: If you want to build and install the kernel with the ``buildkernel'' and ``installkernel'' targets, you might need to build world before. More information is available in the handbook. The sample kernel configuration files reside in the sys/<arch>/conf sub-directory (assuming that you've installed the kernel sources), the file named GENERIC being the one used to build your initial installation kernel. The file NOTES contains entries and documentation for all possible devices, not just those commonly used. It is the successor of the ancient LINT file, but in contrast to LINT, it is not buildable as a kernel but a pure reference and documentation file. Source Roadmap: --------------- bin System/user commands. cddl Various commands and libraries under the Common Development and Distribution License. contrib Packages contributed by 3rd parties. crypto Cryptography stuff (see crypto/README). etc Template files for /etc. games Amusements. gnu Various commands and libraries under the GNU Public License. Please see gnu/COPYING* for more information. include System include files. kerberos5 Kerberos5 (Heimdal) package. lib System libraries. libexec System daemons. release Release building Makefile & associated tools. rescue Build system for statically linked /rescue utilities. sbin System commands. secure Cryptographic libraries and commands. share Shared resources. sys Kernel sources. tools Utilities for regression testing and miscellaneous tasks. usr.bin User commands. usr.sbin System administration commands. For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/synching.html