; 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(...)