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55 lines
728 B
Markdown
55 lines
728 B
Markdown
# lowering
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This C program
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```c
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long main() {
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long a = 0;
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int b = 0;
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return 0;
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}
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```
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should lower into the following unoptimized IR
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```llvmir
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def main() {
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bb0:
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%a = alloca, size=8, align=8
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store %a, 0, size=8, align=8
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%b = alloca, size=4, align=4
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store %b, 0, size=4, align=4
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ret 0
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}
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```
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this IR can then be lowered to very sane machine code ignoring stack alignment which also like matters
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```x86asm
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sub rbp, 8 ; a
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mov [rbp], 0
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sub rbp, 4 ; b
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xor rax, rax
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ret
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```
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---
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```c
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int main()
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{
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int a = 1 + 3 * 4;
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return 0;
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}
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```
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```llvmir
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def main() {
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bb0:
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%a = alloca, size=4, align=4
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%1 = mul 3, 4
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%2 = add 1, %1
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store %a, %2, size=4, align=4
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ret 0
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}
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```
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