40 lines
1.6 KiB
Plaintext
40 lines
1.6 KiB
Plaintext
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# The Problem
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gcc sometimes generates slightly different code with the same semantics.
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## Optimizations
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The following optimizer flags reduce non-determinism when compiling wxWidgets:
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-fno-tree-loop-optimize
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-fno-trapping-math
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-fno-tree-reassoc
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## Left Over
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Even with the above flags, the compiler still generates this difference in one out of 100 builds of wxWidgets:
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monolib_property.o: elf64-elf_x86_64
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aef7: 00
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aef8: 45 31 f6 xor %r14d,%r14d
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aefb: 48 8d 84 24 50 06 00 00 lea 0x650(%rsp),%rax
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- af03: c6 44 24 67 00 movb $0x0,0x67(%rsp)
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- af08: 48 83 c2 10 add $0x10,%rdx
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- af0c: 48 83 c1 10 add $0x10,%rcx
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- af10: 48 81 7c 24 08 ff ff ff cmpq $0xffffff,0x8(%rsp)
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- af18: 00
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- af19: c6 44 24 47 00 movb $0x0,0x47(%rsp)
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- af1e: c7 44 24 24 00 00 00 00 movl $0x0,0x24(%rsp)
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+ af03: c7 44 24 24 00 00 00 00 movl $0x0,0x24(%rsp)
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+ af0b: 48 83 c2 10 add $0x10,%rdx
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+ af0f: 48 83 c1 10 add $0x10,%rcx
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+ af13: 48 81 7c 24 08 ff ff ff cmpq $0xffffff,0x8(%rsp)
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+ af1b: 00
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+ af1c: c6 44 24 47 00 movb $0x0,0x47(%rsp)
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+ af21: c6 44 24 67 00 movb $0x0,0x67(%rsp)
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af26: 4c 8d bc 24 28 03 00 00 lea 0x328(%rsp),%r15
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af2e: 48 89 44 24 10 mov %rax,0x10(%rsp)
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af33: 48 89 54 24 78 mov %rdx,0x78(%rsp)
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