|  | ; RUN: llc < %s -march=x86 | 
|  | ; PR4753 | 
|  |  | 
|  | ; This function has a sub-register reuse undone. | 
|  |  | 
|  | @uint8 = external global i32                      ; <i32*> [#uses=3] | 
|  |  | 
|  | declare signext i8 @foo(i32, i8 signext) nounwind readnone | 
|  |  | 
|  | declare signext i8 @bar(i32, i8 signext) nounwind readnone | 
|  |  | 
|  | define i32 @uint80(i8 signext %p_52) nounwind { | 
|  | entry: | 
|  | %0 = sext i8 %p_52 to i16                       ; <i16> [#uses=1] | 
|  | %1 = tail call i32 @func_24(i16 zeroext %0, i8 signext ptrtoint (i8 (i32, i8)* @foo to i8)) nounwind; <i32> [#uses=1] | 
|  | %2 = trunc i32 %1 to i8                         ; <i8> [#uses=1] | 
|  | %3 = or i8 %2, 1                                ; <i8> [#uses=1] | 
|  | %4 = tail call i32 @safe(i32 1) nounwind        ; <i32> [#uses=0] | 
|  | %5 = tail call i32 @func_24(i16 zeroext 0, i8 signext undef) nounwind; <i32> [#uses=1] | 
|  | %6 = trunc i32 %5 to i8                         ; <i8> [#uses=1] | 
|  | %7 = xor i8 %3, %p_52                           ; <i8> [#uses=1] | 
|  | %8 = xor i8 %7, %6                              ; <i8> [#uses=1] | 
|  | %9 = icmp ne i8 %p_52, 0                        ; <i1> [#uses=1] | 
|  | %10 = zext i1 %9 to i8                          ; <i8> [#uses=1] | 
|  | %11 = tail call i32 @func_24(i16 zeroext ptrtoint (i8 (i32, i8)* @bar to i16), i8 signext %10) nounwind; <i32> [#uses=1] | 
|  | %12 = tail call i32 @func_24(i16 zeroext 0, i8 signext 1) nounwind; <i32> [#uses=0] | 
|  | br i1 undef, label %bb2, label %bb | 
|  |  | 
|  | bb:                                               ; preds = %entry | 
|  | br i1 undef, label %bb2, label %bb3 | 
|  |  | 
|  | bb2:                                              ; preds = %bb, %entry | 
|  | br label %bb3 | 
|  |  | 
|  | bb3:                                              ; preds = %bb2, %bb | 
|  | %iftmp.2.0 = phi i32 [ 0, %bb2 ], [ 1, %bb ]    ; <i32> [#uses=1] | 
|  | %13 = icmp ne i32 %11, %iftmp.2.0               ; <i1> [#uses=1] | 
|  | %14 = tail call i32 @safe(i32 -2) nounwind      ; <i32> [#uses=0] | 
|  | %15 = zext i1 %13 to i8                         ; <i8> [#uses=1] | 
|  | %16 = tail call signext i8 @func_53(i8 signext undef, i8 signext 1, i8 signext %15, i8 signext %8) nounwind; <i8> [#uses=0] | 
|  | br i1 undef, label %bb5, label %bb4 | 
|  |  | 
|  | bb4:                                              ; preds = %bb3 | 
|  | %17 = volatile load i32* @uint8, align 4        ; <i32> [#uses=0] | 
|  | br label %bb5 | 
|  |  | 
|  | bb5:                                              ; preds = %bb4, %bb3 | 
|  | %18 = volatile load i32* @uint8, align 4        ; <i32> [#uses=0] | 
|  | %19 = sext i8 undef to i16                      ; <i16> [#uses=1] | 
|  | %20 = tail call i32 @func_24(i16 zeroext %19, i8 signext 1) nounwind; <i32> [#uses=0] | 
|  | br i1 undef, label %return, label %bb6.preheader | 
|  |  | 
|  | bb6.preheader:                                    ; preds = %bb5 | 
|  | %21 = sext i8 %p_52 to i32                      ; <i32> [#uses=1] | 
|  | %22 = volatile load i32* @uint8, align 4        ; <i32> [#uses=0] | 
|  | %23 = tail call i32 (...)* @safefuncts(i32 %21, i32 1) nounwind; <i32> [#uses=0] | 
|  | unreachable | 
|  |  | 
|  | return:                                           ; preds = %bb5 | 
|  | ret i32 undef | 
|  | } | 
|  |  | 
|  | declare i32 @func_24(i16 zeroext, i8 signext) | 
|  |  | 
|  | declare i32 @safe(i32) | 
|  |  | 
|  | declare signext i8 @func_53(i8 signext, i8 signext, i8 signext, i8 signext) | 
|  |  | 
|  | declare i32 @safefuncts(...) |