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https://github.com/tinygo-org/tinygo.git
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Ayke van Laethem
67de8b490d
The only architecture that actually needs special support for scanning the stack is WebAssembly. All others allow raw access to the stack with a small bit of assembly. Therefore, don't manually keep track of all these objects on the stack manually and instead just use conservative stack scanning. This results in a massive code size decrease in the affected targets (only tested linux/amd64 for code size) - sometimes around 33%. It also allows for future improvements such as using proper stackful goroutines.
30 lines
702 B
ArmAsm
30 lines
702 B
ArmAsm
#ifdef __ELF__
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.section .text.tinygo_scanCurrentStack
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.global tinygo_scanCurrentStack
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tinygo_scanCurrentStack:
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#else // Darwin
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.global _tinygo_scanCurrentStack
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_tinygo_scanCurrentStack:
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#endif
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// Save callee-saved registers.
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pushq %rbx
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pushq %rbp
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pushq %r12
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pushq %r13
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pushq %r14
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pushq %r15
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// Scan the stack.
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subq $8, %rsp // adjust the stack before the call to maintain 16-byte alignment
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movq %rsp, %rdi
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#ifdef __ELF__
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callq tinygo_scanstack
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#else
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callq _tinygo_scanstack // Darwin
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#endif
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// Restore the stack pointer. Registers do not need to be restored as they
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// were only pushed to be discoverable by the GC.
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addq $56, %rsp
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retq
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