dd3ca65c37
Instructions between two adjacent loops will be hoisted above the first loop, or sunk below the second to facilitate loop fusion. Hoisting will be attempted for an instruction that dominates the first loop. Otherwise, sinking this instructions will be attempted. Instructions with side effects will not be considered for sinking or hoisting. Hoisting/sinking of any instructions between loops will only be performed if all the instructions can be moved. As well, sinking/hoisting is considered for each instruction in isolation, without taking into account sinking/hoisting decisions for other instructions in the preheader. Differential Revision: https://reviews.llvm.org/D118076
34 lines
744 B
LLVM
34 lines
744 B
LLVM
; RUN: opt -S -loop-fusion < %s | FileCheck %s
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define void @hoist_preheader(i32 %N) {
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; CHECK:pre1:
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; CHECK-NEXT: %hoistme = add i32 1, %N
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; CHECK-NEXT: %hoistme2 = add i32 1, %hoistme
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; CHECK-NEXT: br label %body1
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pre1:
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br label %body1
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; CHECK: body1:
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; CHECK-NOT: %hoistme
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body1: ; preds = %pre1, %body1
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%i = phi i32 [%i_next, %body1], [0, %pre1]
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%i_next = add i32 1, %i
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%cond = icmp ne i32 %i, %N
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br i1 %cond, label %body1, label %pre2
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pre2:
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%hoistme = add i32 1, %N
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%hoistme2 = add i32 1, %hoistme
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br label %body2
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body2: ; preds = %pre2, %body2
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%i2 = phi i32 [%i_next2, %body2], [0, %pre2]
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%i_next2 = add i32 1, %i2
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%cond2 = icmp ne i32 %i2, %N
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br i1 %cond2, label %body2, label %exit
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exit:
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ret void
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}
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