llvm-6502/lib/ExecutionEngine/JIT
Evan Cheng 1606e8e4cd Fix some significant problems with constant pools that resulted in unnecessary paddings between constant pool entries, larger than necessary alignments (e.g. 8 byte alignment for .literal4 sections), and potentially other issues.
1. ConstantPoolSDNode alignment field is log2 value of the alignment requirement. This is not consistent with other SDNode variants.
2. MachineConstantPool alignment field is also a log2 value.
3. However, some places are creating ConstantPoolSDNode with alignment value rather than log2 values. This creates entries with artificially large alignments, e.g. 256 for SSE vector values.
4. Constant pool entry offsets are computed when they are created. However, asm printer group them by sections. That means the offsets are no longer valid. However, asm printer uses them to determine size of padding between entries.
5. Asm printer uses expensive data structure multimap to track constant pool entries by sections.
6. Asm printer iterate over SmallPtrSet when it's emitting constant pool entries. This is non-deterministic.


Solutions:
1. ConstantPoolSDNode alignment field is changed to keep non-log2 value.
2. MachineConstantPool alignment field is also changed to keep non-log2 value.
3. Functions that create ConstantPool nodes are passing in non-log2 alignments.
4. MachineConstantPoolEntry no longer keeps an offset field. It's replaced with an alignment field. Offsets are not computed when constant pool entries are created. They are computed on the fly in asm printer and JIT.
5. Asm printer uses cheaper data structure to group constant pool entries.
6. Asm printer compute entry offsets after grouping is done.
7. Change JIT code to compute entry offsets on the fly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66875 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-13 07:51:59 +00:00
..
CMakeLists.txt Initial support for the CMake build system. 2008-09-22 01:08:49 +00:00
Intercept.cpp Fix misplaced right parentheses. 2009-01-05 17:17:04 +00:00
JIT.cpp Introduce new linkage types linkonce_odr, weak_odr, common_odr 2009-03-07 15:45:40 +00:00
JIT.h Add support to the JIT for true non-lazy operation. When a call to a function 2009-02-18 08:31:02 +00:00
JITDwarfEmitter.cpp On 64bit we may have a personality function which requires 64 bits to 2009-02-15 20:49:23 +00:00
JITDwarfEmitter.h Cosmetic changes, as suggested by Evan. No functionality changes. 2008-04-20 17:44:19 +00:00
JITEmitter.cpp Fix some significant problems with constant pools that resulted in unnecessary paddings between constant pool entries, larger than necessary alignments (e.g. 8 byte alignment for .literal4 sections), and potentially other issues. 2009-03-13 07:51:59 +00:00
JITMemoryManager.cpp Fix PR3724 by searching for the largest free block when 2009-03-09 21:34:10 +00:00
Makefile Removed trailing whitespace from Makefiles. 2009-01-09 16:44:42 +00:00
TargetSelect.cpp Registry.h should not depend on CommandLine.h. 2009-01-16 07:02:28 +00:00