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llvm-project/llvm/test/CodeGen/PowerPC/func-addr.ll

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Use PIC relocation model as default for PowerPC64 ELF. Most of the PowerPC64 code generation for the ELF ABI is already PIC. There are four main exceptions: (1) Constant pointer arrays etc. should in writeable sections. (2) The TOC restoration NOP after a call is needed for all global symbols. While GNU ld has a workaround for questionable GCC self-calls, we trigger the checks for calls from COMDAT sections as they cross input sections and are therefore not considered self-calls. The current decision is questionable and suboptimal, but outside the scope of the change. (3) TLS access can not use the initial-exec model. (4) Jump tables should use relative addresses. Note that the current encoding doesn't work for the large code model, but it is more compact than the default for any non-trivial jump table. Improving this is again beyond the scope of this change. At least (1) and (3) are assumptions made in target-independent code and introducing additional hooks is a bit messy. Testing with clang shows that a -fPIC binary is 600KB smaller than the corresponding -fno-pic build. Separate testing from improved jump table encodings would explain only about 100KB or so. The rest is expected to be a result of more aggressive immediate forming for -fno-pic, where the -fPIC binary just uses TOC entries. This change brings the LLVM output in line with the GCC output, other PPC64 compilers like XLC on AIX are known to produce PIC by default as well. The relocation model can still be provided explicitly, i.e. when using MCJIT. One test case for case (1) is included, other test cases with relocation mode sensitive behavior are wired to static for now. They will be reviewed and adjusted separately. Differential Revision: https://reviews.llvm.org/D26566 llvm-svn: 289743
2016-12-15 08:01:53 +08:00
; RUN: llc -relocation-model=static -verify-machineinstrs -mtriple powerpc64-linux < %s | FileCheck %s
; RUN: llc -relocation-model=static -verify-machineinstrs -O0 -mtriple powerpc64-linux < %s | FileCheck %s
Add a test showing the ppc code sequence for getting a function pointer. This would have found the miscompile in r209638. llvm-svn: 209820
2014-05-29 23:13:23 +08:00
define void @foo() {
ret void
}
declare i32 @bar(i8*)
; CHECK-LABEL: {{^}}zed:
[PPC64] Fix PR19893 - improve code generation for local function addresses Rafael opened http://llvm.org/bugs/show_bug.cgi?id=19893 to track non-optimal code generation for forming a function address that is local to the compile unit. The existing code was treating both local and non-local functions identically. This patch fixes the problem by properly identifying local functions and generating the proper addis/addi code. I also noticed that Rafael's earlier changes to correct the surrounding code in PPCISelLowering.cpp were also needed for fast instruction selection in PPCFastISel.cpp, so this patch fixes that code as well. The existing test/CodeGen/PowerPC/func-addr.ll is modified to test the new code generation. I've added a -O0 run line to test the fast-isel code as well. Tested on powerpc64[le]-unknown-linux-gnu with no regressions. llvm-svn: 211056
2014-06-17 05:36:02 +08:00
; CHECK: addis 3, 2, foo@toc@ha
; CHECK-NEXT: addi 3, 3, foo@toc@l
Add a test showing the ppc code sequence for getting a function pointer. This would have found the miscompile in r209638. llvm-svn: 209820
2014-05-29 23:13:23 +08:00
; CHECK-NEXT: bl bar
define void @zed() {
call i32 @bar(i8* bitcast (void ()* @foo to i8*))
ret void
}