82 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			82 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			LLVM
		
	
	
	
; RUN: llc -mtriple=x86_64-linux-gnu %s -o - -jump-table-density=25 | FileCheck %s --check-prefix=DENSE --check-prefix=CHECK
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; RUN: llc -mtriple=x86_64-linux-gnu %s -o - -jump-table-density=10 | FileCheck %s --check-prefix=SPARSE --check-prefix=CHECK
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declare void @g(i32)
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define void @sparse(i32 %x) {
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entry:
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  switch i32 %x, label %return [
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    i32 300, label %bb0
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    i32 100, label %bb1
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    i32 400, label %bb1
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    i32 500, label %bb2
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  ]
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bb0: tail call void @g(i32 0) br label %return
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bb1: tail call void @g(i32 1) br label %return
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bb2: tail call void @g(i32 1) br label %return
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return: ret void
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; Should pivot around 400 for two subtrees with two jump tables each.
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; CHECK-LABEL: sparse
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; CHECK-NOT: cmpl
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; CHECK: cmpl $399
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; CHECK: cmpl $100
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; CHECK: cmpl $300
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; CHECK: cmpl $400
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; CHECK: cmpl $500
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}
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define void @med(i32 %x) {
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entry:
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  switch i32 %x, label %return [
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    i32 30, label %bb0
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    i32 10, label %bb1
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    i32 40, label %bb1
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    i32 50, label %bb2
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    i32 20, label %bb3
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  ]
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bb0: tail call void @g(i32 0) br label %return
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bb1: tail call void @g(i32 1) br label %return
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bb2: tail call void @g(i32 1) br label %return
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bb3: tail call void @g(i32 2) br label %return
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return: ret void
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; Lowered as a jump table when sparse, and branches when dense.
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; CHECK-LABEL: med
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; SPARSE: addl $-10
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; SPARSE: cmpl $40
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; SPARSE: ja
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; SPARSE: jmpq *.LJTI
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; DENSE-NOT: cmpl
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; DENSE: cmpl $29
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; DENSE-DAG: cmpl $10
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; DENSE-DAG: cmpl $20
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; DENSE-DAG: cmpl $30
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; DENSE-DAG: cmpl $40
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; DENSE-DAG: cmpl $50
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; DENSE: retq
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}
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define void @dense(i32 %x) {
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entry:
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  switch i32 %x, label %return [
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    i32 12, label %bb0
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    i32 4,  label %bb1
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    i32 16, label %bb1
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    i32 20, label %bb2
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    i32 8,  label %bb3
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  ]
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bb0: tail call void @g(i32 0) br label %return
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bb1: tail call void @g(i32 1) br label %return
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bb2: tail call void @g(i32 1) br label %return
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bb3: tail call void @g(i32 2) br label %return
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return: ret void
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; Lowered as a jump table when sparse, and branches when dense.
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; CHECK-LABEL: dense
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; CHECK: addl $-4
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; CHECK: cmpl $16
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; CHECK: ja
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; CHECK: jmpq *.LJTI
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}
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