llvm-6502/test/CodeGen/X86/switch-bt.ll
Dan Gohman 8e0163ac1e Optimize the "bit test" code path for switch lowering in the
case where the bit mask has exactly one bit.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106716 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-24 02:06:24 +00:00

52 lines
1.5 KiB
LLVM

; RUN: llc -march=x86-64 -asm-verbose=false < %s | FileCheck %s
; This switch should use bit tests, and the third bit test case is just
; testing for one possible value, so it doesn't need a bt.
; CHECK: movabsq $2305843009482129440, %r
; CHECK-NEXT: btq %rax, %r
; CHECK-NEXT: jb
; CHECK-NEXT: movl $671088640, %e
; CHECK-NEXT: btq %rax, %r
; CHECK-NEXT: jb
; CHECK-NEXT: testq %rax, %r
; CHECK-NEXT: j
define void @test(i8* %l) nounwind {
entry:
%l.addr = alloca i8*, align 8 ; <i8**> [#uses=2]
store i8* %l, i8** %l.addr
%tmp = load i8** %l.addr ; <i8*> [#uses=1]
%tmp1 = load i8* %tmp ; <i8> [#uses=1]
%conv = sext i8 %tmp1 to i32 ; <i32> [#uses=1]
switch i32 %conv, label %sw.default [
i32 62, label %sw.bb
i32 60, label %sw.bb
i32 38, label %sw.bb2
i32 94, label %sw.bb2
i32 61, label %sw.bb2
i32 33, label %sw.bb4
]
sw.bb: ; preds = %entry, %entry
call void @foo(i32 0)
br label %sw.epilog
sw.bb2: ; preds = %entry, %entry, %entry
call void @foo(i32 1)
br label %sw.epilog
sw.bb4: ; preds = %entry
call void @foo(i32 3)
br label %sw.epilog
sw.default: ; preds = %entry
call void @foo(i32 97)
br label %sw.epilog
sw.epilog: ; preds = %sw.default, %sw.bb4, %sw.bb2, %sw.bb
ret void
}
declare void @foo(i32)