44 lines
976 B
Plaintext
44 lines
976 B
Plaintext
# Programs from "Global Code Motion Global Value Numbering" by Cliff Click
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# https://courses.cs.washington.edu/courses/cse501/06wi/reading/click-pldi95.pdf
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# GCM program in Figure 1
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function w $gcm_test(w %a){
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@start
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%i.0 =w copy 0
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@loop
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%i.1 =w phi @start %i.0, @loop %i.2
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%b =w add %a, 1 # early schedule moves to @start
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%i.2 =w add %i.1, %b
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%c =w mul %i.2, 2 # late schedule moves to @end
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%x =w csltw %i.2, 10
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jnz %x, @loop, @end
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@end
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ret %c
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}
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# GCM program in "Figure 3 x's definition does not dominate it's use"
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#
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# SSA contruction will insert phi instruction for "x" in @if_false
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# preventing the "add" in @if_false from being moved to @if_true
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function $gcm_test2 (w %a){
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@start
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%f =w copy 1
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%x =w copy 0
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%s.0 =w copy 0
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@loop
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%s.1 = w phi @start %s.0, @if_false %s.2
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jnz %a, @if, @end
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@if
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jnz %f, @if_true, @if_false
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@if_true
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%f =w copy 0
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%x =w add %x, 1
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@if_false
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%s.2 =w add %s.1, %x
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jmp @loop
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@end
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ret
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}
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