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author | Magnus Lång <[email protected]> | 2016-05-11 13:39:53 +0200 |
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committer | Magnus Lång <[email protected]> | 2016-05-11 13:39:53 +0200 |
commit | 7814ec18b095d40af95f362ff668a68915982e45 (patch) | |
tree | 50f16b9f246275c12843bbc8270cb0529aa86bd6 /lib/hipe/llvm | |
parent | 0f489445070cf65d96db7938f80ad118921c1f6a (diff) | |
download | otp-7814ec18b095d40af95f362ff668a68915982e45.tar.gz otp-7814ec18b095d40af95f362ff668a68915982e45.tar.bz2 otp-7814ec18b095d40af95f362ff668a68915982e45.zip |
hipe_llvm: Allow LLVM-generated constants
Since 3.7, LLVM sometimes generates SSE constants in a special constant
section with the requisite alignment (".rodata.cst16"). This broke
hipe_llvm since it assumed that all constants that were linked from the
text section were constants generated by hipe_llvm.
As this is the first time alignments larger than 8 have been required,
some small changes were required to hipe_consttab and
hipe_bifs:alloc_data/2. Note that hipe_bifs:alloc_data/2 still assumes
that erl_alloc will provide the requisite alignment.
Diffstat (limited to 'lib/hipe/llvm')
-rw-r--r-- | lib/hipe/llvm/elf_format.erl | 7 | ||||
-rw-r--r-- | lib/hipe/llvm/hipe_llvm_main.erl | 31 |
2 files changed, 35 insertions, 3 deletions
diff --git a/lib/hipe/llvm/elf_format.erl b/lib/hipe/llvm/elf_format.erl index 4155dff7c4..b3c5ecddab 100644 --- a/lib/hipe/llvm/elf_format.erl +++ b/lib/hipe/llvm/elf_format.erl @@ -23,6 +23,8 @@ get_exn_handlers/1, %% Symbols elf_symbols/1, + %% Sections + section_contents/2, %% Main interface read/1 ]). @@ -312,6 +314,11 @@ elf_section(?SHN_ABS, #elf{}) -> abs; elf_section(Index, #elf{sec_idx=SecIdx}) when Index =< tuple_size(SecIdx) -> element(Index, SecIdx). +%% Reads the contents of a section from an object +-spec section_contents(elf_shdr(), elf()) -> binary(). +section_contents(#elf_shdr{offset=Offset, size=Size}, #elf{file=ElfBin}) -> + get_binary_segment(ElfBin, Offset, Size). + %%------------------------------------------------------------------------------ %% Functions to manipulate Symbol Table %%------------------------------------------------------------------------------ diff --git a/lib/hipe/llvm/hipe_llvm_main.erl b/lib/hipe/llvm/hipe_llvm_main.erl index 3ab213f94c..476d6fb49c 100644 --- a/lib/hipe/llvm/hipe_llvm_main.erl +++ b/lib/hipe/llvm/hipe_llvm_main.erl @@ -13,7 +13,7 @@ %% chain is invoked in order to produce an object file. rtl_to_native(MFA, RTL, Roots, Options) -> %% Compile to LLVM and get Instruction List (along with infos) - {LLVMCode, RelocsDict, ConstTab} = + {LLVMCode, RelocsDict0, ConstTab0} = hipe_rtl_to_llvm:translate(RTL, Roots), %% Fix function name to an acceptable LLVM identifier (needed for closures) {_Module, Fun, Arity} = hipe_rtl_to_llvm:fix_mfa_name(MFA), @@ -32,10 +32,11 @@ rtl_to_native(MFA, RTL, Roots, Options) -> {SwitchInfos, ExposedClosures} = correlate_labels(Tables, Labels), %% SwitchInfos: [{"table_50", [Labels]}] %% ExposedClosures: [{"table_closures", [Labels]}] - + %% Labelmap contains the offsets of the labels in the code that are %% used for switch's jump tables - LabelMap = create_labelmap(MFA, SwitchInfos, RelocsDict), + LabelMap = create_labelmap(MFA, SwitchInfos, RelocsDict0), + {RelocsDict, ConstTab} = extract_constants(RelocsDict0, ConstTab0, Obj), %% Get relocation info TextRelocs = elf_format:extract_rela(Obj, ?TEXT), %% AccRefs contains the offsets of all references to relocatable symbols in @@ -219,6 +220,25 @@ insert_to_labelmap([{Key, Value}|Rest], LabelMap) -> insert_to_labelmap(Rest, LabelMap) end. +%% Find any LLVM-generated constants and add them to the constant table +extract_constants(RelocsDict0, ConstTab0, Obj) -> + TextRelocs = elf_format:extract_rela(Obj, ?TEXT), + AnonConstSections = + lists:usort([{Sec, Offset} + || #elf_rel{symbol=#elf_sym{type=section, section=Sec}, + addend=Offset} <- TextRelocs]), + lists:foldl( + fun({#elf_shdr{name=Name, type=progbits, addralign=Align, entsize=EntSize, + size=Size} = Section, Offset}, {RelocsDict1, ConstTab1}) + when EntSize > 0, 0 =:= Size rem EntSize, 0 =:= Offset rem EntSize -> + SectionBin = elf_format:section_contents(Section, Obj), + Constant = binary:part(SectionBin, Offset, EntSize), + {ConstTab, ConstLbl} = + hipe_consttab:insert_binary_const(ConstTab1, Align, Constant), + {dict:store({anon, Name, Offset}, {constant, ConstLbl}, RelocsDict1), + ConstTab} + end, {RelocsDict0, ConstTab0}, AnonConstSections). + %% @doc Correlate object file relocation symbols with info from translation to %% llvm code. fix_relocations(Relocs, RelocsDict, MFA) -> @@ -269,6 +289,11 @@ fix_reloc(#elf_rel{symbol=#elf_sym{name=Name, section=#elf_shdr{name=?RODATA}, case dict:fetch(Name, RelocsDict) of {switch, _, JTabLab} -> %% Treat switch exactly as constant {?LOAD_ADDRESS, Offset, {constant, JTabLab}} + end; +fix_reloc(#elf_rel{symbol=#elf_sym{type=section, section=#elf_shdr{name=Name}}, + offset=Offset, type=?ABS_T, addend=Addend}, RelocsDict, _) -> + case dict:fetch({anon, Name, Addend}, RelocsDict) of + {constant, Label} -> {?LOAD_ADDRESS, Offset, {constant, Label}} end. %%------------------------------------------------------------------------------ |