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llvm-project/llvm/test/CodeGen/AArch64/max-jump-table.ll

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[AArch64] Fix test triplet Specify proper target triplet to pass under Windows too. llvm-svn: 282423
2016-09-27 02:09:21 +08:00
; RUN: llc %s -O2 -print-machineinstrs -mtriple=aarch64-linux-gnu -jump-table-density=40 -o - 2>%t; FileCheck %s --check-prefixes=CHECK,CHECK0 <%t
; RUN: llc %s -O2 -print-machineinstrs -mtriple=aarch64-linux-gnu -jump-table-density=40 -max-jump-table=4 -o - 2>%t; FileCheck %s --check-prefixes=CHECK,CHECK4 <%t
; RUN: llc %s -O2 -print-machineinstrs -mtriple=aarch64-linux-gnu -jump-table-density=40 -max-jump-table=8 -o - 2>%t; FileCheck %s --check-prefixes=CHECK,CHECK8 <%t
; RUN: llc %s -O2 -print-machineinstrs -mtriple=aarch64-linux-gnu -jump-table-density=40 -mcpu=exynos-m1 -o - 2>%t; FileCheck %s --check-prefixes=CHECK,CHECKM1 <%t
Add support to optionally limit the size of jump tables. Many high-performance processors have a dedicated branch predictor for indirect branches, commonly used with jump tables. As sophisticated as such branch predictors are, they tend to have well defined limits beyond which their effectiveness is hampered or even nullified. One such limit is the number of possible destinations for a given indirect branches that such branch predictors can handle. This patch considers a limit that a target may set to the number of destination addresses in a jump table. Patch by: Evandro Menezes <e.menezes@samsung.com>, Aditya Kumar <aditya.k7@samsung.com>, Sebastian Pop <s.pop@samsung.com>. Differential revision: https://reviews.llvm.org/D21940 llvm-svn: 282412
2016-09-26 23:32:33 +08:00
declare void @ext(i32)
define i32 @jt1(i32 %a, i32 %b) {
entry:
switch i32 %a, label %return [
i32 1, label %bb1
i32 2, label %bb2
i32 3, label %bb3
i32 4, label %bb4
i32 5, label %bb5
i32 6, label %bb6
i32 7, label %bb7
i32 8, label %bb8
i32 9, label %bb9
i32 10, label %bb10
i32 11, label %bb11
i32 12, label %bb12
i32 13, label %bb13
i32 14, label %bb14
i32 15, label %bb15
i32 16, label %bb16
i32 17, label %bb17
]
; CHECK-LABEL: function jt1:
; CHECK: Jump Tables:
; CHECK0-NEXT: jt#0:
; CHECK0-NOT: jt#1:
; CHECK4-NEXT: jt#0:
; CHECK4-SAME: jt#1:
; CHECK4-SAME: jt#2:
; CHECK4-SAME: jt#3:
; CHECK4-NOT: jt#4:
; CHECK8-NEXT: jt#0:
; CHECK8-SAME: jt#1:
; CHECK8-SAME: jt#2: BB#14 BB#15 BB#16 BB#17{{$}}
; CHECK8-NOT: jt#3:
; CHECKM1-NEXT: jt#0:
; CHECKM1-SAME: jt#1: BB#13 BB#14 BB#15 BB#16 BB#17{{$}}
; CHECKM1-NOT: jt#2:
; CHEC-NEXT: Function Live Ins:
bb1: tail call void @ext(i32 0) br label %return
bb2: tail call void @ext(i32 2) br label %return
bb3: tail call void @ext(i32 4) br label %return
bb4: tail call void @ext(i32 6) br label %return
bb5: tail call void @ext(i32 8) br label %return
bb6: tail call void @ext(i32 10) br label %return
bb7: tail call void @ext(i32 12) br label %return
bb8: tail call void @ext(i32 14) br label %return
bb9: tail call void @ext(i32 16) br label %return
bb10: tail call void @ext(i32 18) br label %return
bb11: tail call void @ext(i32 20) br label %return
bb12: tail call void @ext(i32 22) br label %return
bb13: tail call void @ext(i32 24) br label %return
bb14: tail call void @ext(i32 26) br label %return
bb15: tail call void @ext(i32 28) br label %return
bb16: tail call void @ext(i32 30) br label %return
bb17: tail call void @ext(i32 32) br label %return
return: ret i32 %b
}
define void @jt2(i32 %x) {
entry:
switch i32 %x, label %return [
i32 1, label %bb1
i32 2, label %bb2
i32 3, label %bb3
i32 4, label %bb4
i32 14, label %bb5
i32 15, label %bb6
]
; CHECK-LABEL: function jt2:
; CHECK: Jump Tables:
; CHECK0-NEXT: jt#0: BB#1 BB#2 BB#3 BB#4 BB#7 BB#7 BB#7 BB#7 BB#7 BB#7 BB#7 BB#7 BB#7 BB#5 BB#6{{$}}
; CHECK4-NEXT: jt#0: BB#1 BB#2 BB#3 BB#4{{$}}
; CHECK8-NEXT: jt#0: BB#1 BB#2 BB#3 BB#4{{$}}
; CHECKM1-NEXT: jt#0: BB#1 BB#2 BB#3 BB#4{{$}}
; CHEC-NEXT: Function Live Ins:
bb1: tail call void @ext(i32 1) br label %return
bb2: tail call void @ext(i32 2) br label %return
bb3: tail call void @ext(i32 3) br label %return
bb4: tail call void @ext(i32 4) br label %return
bb5: tail call void @ext(i32 5) br label %return
bb6: tail call void @ext(i32 6) br label %return
return: ret void
}