52 lines
1.5 KiB
ArmAsm
52 lines
1.5 KiB
ArmAsm
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# 22 october 2017
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# clang -o writewidths writewidths.c writewidths.s -g -Wall -Wextra -pedantic -g
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# thanks to:
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# - http://www.idryman.org/blog/2014/12/02/writing-64-bit-assembly-on-mac-os-x/
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# - https://developer.apple.com/library/content/documentation/DeveloperTools/Reference/Assembler/060-i386_Addressing_Modes_and_Assembler_Instructions/i386_intructions.html#//apple_ref/doc/uid/TP30000825-TPXREF101
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# - https://stackoverflow.com/questions/46309041/trivial-macos-assembly-64-bit-program-has-incorrect-stack-alignment
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# - https://www.google.com/search?q=macos+implement+main+in+assembly+-nasm&oq=macos+implement+main+in+assembly+-nasm&gs_l=psy-ab.3...12877.13839.0.13988.6.6.0.0.0.0.117.407.4j1.5.0....0...1.1.64.psy-ab..1.0.0....0.et6MkokjvwA
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# - https://stackoverflow.com/questions/2529185/what-are-cfi-directives-in-gnu-assembler-gas-used-for
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.section __DATA,__data
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double10:
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.quad 0x4024000000000000
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doubleNeg05:
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.quad 0xbfe0000000000000
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fmt:
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.asciz "unregistered OS2 %ld:\tfloat64as(%g, 0x%016lx)\n"
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.section __TEXT,__text
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.globl _realMain
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_realMain:
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pushq %rbp
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movq %rsp, %rbp
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addq $8, %rsp
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xorq %rcx, %rcx
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loop:
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pushq %rcx
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# the code from core text
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movzwl %cx, %ecx
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xorps %xmm0, %xmm0
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cvtsi2sdl %ecx, %xmm0
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divsd double10(%rip), %xmm0
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addsd doubleNeg05(%rip), %xmm0
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# end core text code
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popq %rcx
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pushq %rcx
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movd %xmm0, %rdx
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movzwq %cx, %rsi
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leaq fmt(%rip), %rdi
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callq _printf
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popq %rcx
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incw %cx
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cmpw $10, %cx
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jbe loop
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xorq %rax, %rax
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subq $8, %rsp
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popq %rbp
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ret
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