13ca0c87ed
__heap_base was not aligned. In practice, it will often be aligned
simply because it follows the stack, but when the stack is placed at the
beginning (with the --stack-first option), the __heap_base might be
unaligned. It could even be byte-aligned.
At least wasi-libc appears to expect that __heap_base is aligned:
659ff41456/dlmalloc/src/malloc.c (L5224)
While WebAssembly itself does not appear to require any alignment for
memory accesses, it is sometimes required when sharing a pointer
externally. For example, WASI might expect alignment up to 8:
https://github.com/WebAssembly/WASI/blob/main/phases/snapshot/docs.md#-timestamp-u64
This issue got introduced with the addition of the --stack-first flag:
https://reviews.llvm.org/D46141
I suspect the lack of alignment wasn't intentional here.
Differential Revision: https://reviews.llvm.org/D106499
12 lines
194 B
ArmAsm
12 lines
194 B
ArmAsm
.globl _start
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_start:
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.functype _start () -> ()
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end_function
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.globl someByte
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.type someByte,@object
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.section .data.someByte,"",@
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someByte:
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.int8 42
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.size someByte, 1
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