test/Transforms/FunctionAttrs/arg_returned.ll - llvm-project/llvm - Git at Google

 ; RUN: opt -passes=function-attrs -S < %s | FileCheck %s --check-prefix=FNATTR
 ;
 ; Test cases specifically designed for the "returned" argument attribute.
 ; We use FIXME's to indicate problems and missing attributes.
 ;

 ; TEST SCC test returning an integer value argument
 ;
 ;
 ; FNATTR: define i32 @sink_r0(i32 returned %r)
 ; FNATTR: define i32 @scc_r1(i32 %a, i32 %r, i32 %b)
 ; FNATTR: define i32 @scc_r2(i32 %a, i32 %b, i32 %r)
 ; FNATTR: define i32 @scc_rX(i32 %a, i32 %b, i32 %r)
 ;
 ;
 ; int scc_r1(int a, int b, int r);
 ; int scc_r2(int a, int b, int r);
 ;
 ; __attribute__((noinline)) int sink_r0(int r) {
 ;   return r;
 ; }
 ;
 ; __attribute__((noinline)) int scc_r1(int a, int r, int b) {
 ;   return scc_r2(r, a, sink_r0(r));
 ; }
 ;
 ; __attribute__((noinline)) int scc_r2(int a, int b, int r) {
 ;   if (a > b)
 ;     return scc_r2(b, a, sink_r0(r));
 ;   if (a < b)
 ;     return scc_r1(sink_r0(b), scc_r2(scc_r1(a, b, r), scc_r1(a, scc_r2(r, r, r), r), scc_r2(a, b, r)), scc_r1(a, b, r));
 ;   return a == b ? r : scc_r2(a, b, r);
 ; }
 ; __attribute__((noinline)) int scc_rX(int a, int b, int r) {
 ;   if (a > b)
 ;     return scc_r2(b, a, sink_r0(r));
 ;   if (a < b)                                                                         // V Diff to scc_r2
 ;     return scc_r1(sink_r0(b), scc_r2(scc_r1(a, b, r), scc_r1(a, scc_r2(r, r, r), r), scc_r1(a, b, r)), scc_r1(a, b, r));
 ;   return a == b ? r : scc_r2(a, b, r);
 ; }
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"

 define i32 @sink_r0(i32 %r) #0 {
 entry:
   ret i32 %r
 }

 define i32 @scc_r1(i32 %a, i32 %r, i32 %b) #0 {
 entry:
   %call = call i32 @sink_r0(i32 %r)
   %call1 = call i32 @scc_r2(i32 %r, i32 %a, i32 %call)
   ret i32 %call1
 }

 define i32 @scc_r2(i32 %a, i32 %b, i32 %r) #0 {
 entry:
   %cmp = icmp sgt i32 %a, %b
   br i1 %cmp, label %if.then, label %if.end

 if.then:                                          ; preds = %entry
   %call = call i32 @sink_r0(i32 %r)
   %call1 = call i32 @scc_r2(i32 %b, i32 %a, i32 %call)
   br label %return

 if.end:                                           ; preds = %entry
   %cmp2 = icmp slt i32 %a, %b
   br i1 %cmp2, label %if.then3, label %if.end12

 if.then3:                                         ; preds = %if.end
   %call4 = call i32 @sink_r0(i32 %b)
   %call5 = call i32 @scc_r1(i32 %a, i32 %b, i32 %r)
   %call6 = call i32 @scc_r2(i32 %r, i32 %r, i32 %r)
   %call7 = call i32 @scc_r1(i32 %a, i32 %call6, i32 %r)
   %call8 = call i32 @scc_r2(i32 %a, i32 %b, i32 %r)
   %call9 = call i32 @scc_r2(i32 %call5, i32 %call7, i32 %call8)
   %call10 = call i32 @scc_r1(i32 %a, i32 %b, i32 %r)
   %call11 = call i32 @scc_r1(i32 %call4, i32 %call9, i32 %call10)
   br label %return

 if.end12:                                         ; preds = %if.end
   %cmp13 = icmp eq i32 %a, %b
   br i1 %cmp13, label %cond.true, label %cond.false

 cond.true:                                        ; preds = %if.end12
   br label %cond.end

 cond.false:                                       ; preds = %if.end12
   %call14 = call i32 @scc_r2(i32 %a, i32 %b, i32 %r)
   br label %cond.end

 cond.end:                                         ; preds = %cond.false, %cond.true
   %cond = phi i32 [ %r, %cond.true ], [ %call14, %cond.false ]
   br label %return

 return:                                           ; preds = %cond.end, %if.then3, %if.then
   %retval.0 = phi i32 [ %call1, %if.then ], [ %call11, %if.then3 ], [ %cond, %cond.end ]
   ret i32 %retval.0
 }

 define i32 @scc_rX(i32 %a, i32 %b, i32 %r) #0 {
 entry:
   %cmp = icmp sgt i32 %a, %b
   br i1 %cmp, label %if.then, label %if.end

 if.then:                                          ; preds = %entry
   %call = call i32 @sink_r0(i32 %r)
   %call1 = call i32 @scc_r2(i32 %b, i32 %a, i32 %call)
   br label %return

 if.end:                                           ; preds = %entry
   %cmp2 = icmp slt i32 %a, %b
   br i1 %cmp2, label %if.then3, label %if.end12

 if.then3:                                         ; preds = %if.end
   %call4 = call i32 @sink_r0(i32 %b)
   %call5 = call i32 @scc_r1(i32 %a, i32 %b, i32 %r)
   %call6 = call i32 @scc_r2(i32 %r, i32 %r, i32 %r)
   %call7 = call i32 @scc_r1(i32 %a, i32 %call6, i32 %r)
   %call8 = call i32 @scc_r1(i32 %a, i32 %b, i32 %r)
   %call9 = call i32 @scc_r2(i32 %call5, i32 %call7, i32 %call8)
   %call10 = call i32 @scc_r1(i32 %a, i32 %b, i32 %r)
   %call11 = call i32 @scc_r1(i32 %call4, i32 %call9, i32 %call10)
   br label %return

 if.end12:                                         ; preds = %if.end
   %cmp13 = icmp eq i32 %a, %b
   br i1 %cmp13, label %cond.true, label %cond.false

 cond.true:                                        ; preds = %if.end12
   br label %cond.end

 cond.false:                                       ; preds = %if.end12
   %call14 = call i32 @scc_r2(i32 %a, i32 %b, i32 %r)
   br label %cond.end

 cond.end:                                         ; preds = %cond.false, %cond.true
   %cond = phi i32 [ %r, %cond.true ], [ %call14, %cond.false ]
   br label %return

 return:                                           ; preds = %cond.end, %if.then3, %if.then
   %retval.0 = phi i32 [ %call1, %if.then ], [ %call11, %if.then3 ], [ %cond, %cond.end ]
   ret i32 %retval.0
 }


 ; TEST SCC test returning a pointer value argument
 ;
 ; FNATTR: define ptr @ptr_sink_r0(ptr readnone returned %r)
 ; FNATTR: define ptr @ptr_scc_r1(ptr %a, ptr readnone %r, ptr nocapture readnone %b)
 ; FNATTR: define ptr @ptr_scc_r2(ptr readnone %a, ptr readnone %b, ptr readnone %r)
 ;
 ;
 ; ptr ptr_scc_r1(ptr a, ptr b, ptr r);
 ; ptr ptr_scc_r2(ptr a, ptr b, ptr r);
 ;
 ; __attribute__((noinline)) ptr ptr_sink_r0(ptr r) {
 ;   return r;
 ; }
 ;
 ; __attribute__((noinline)) ptr ptr_scc_r1(ptr a, ptr r, ptr b) {
 ;   return ptr_scc_r2(r, a, ptr_sink_r0(r));
 ; }
 ;
 ; __attribute__((noinline)) ptr ptr_scc_r2(ptr a, ptr b, ptr r) {
 ;   if (a > b)
 ;     return ptr_scc_r2(b, a, ptr_sink_r0(r));
 ;   if (a < b)
 ;     return ptr_scc_r1(ptr_sink_r0(b), ptr_scc_r2(ptr_scc_r1(a, b, r), ptr_scc_r1(a, ptr_scc_r2(r, r, r), r), ptr_scc_r2(a, b, r)), ptr_scc_r1(a, b, r));
 ;   return a == b ? r : ptr_scc_r2(a, b, r);
 ; }
 define ptr @ptr_sink_r0(ptr %r) #0 {
 entry:
   ret ptr %r
 }

 define ptr @ptr_scc_r1(ptr %a, ptr %r, ptr %b) #0 {
 entry:
   %call = call ptr @ptr_sink_r0(ptr %r)
   %call1 = call ptr @ptr_scc_r2(ptr %r, ptr %a, ptr %call)
   ret ptr %call1
 }

 define ptr @ptr_scc_r2(ptr %a, ptr %b, ptr %r) #0 {
 entry:
   %cmp = icmp ugt ptr %a, %b
   br i1 %cmp, label %if.then, label %if.end

 if.then:                                          ; preds = %entry
   %call = call ptr @ptr_sink_r0(ptr %r)
   %call1 = call ptr @ptr_scc_r2(ptr %b, ptr %a, ptr %call)
   br label %return

 if.end:                                           ; preds = %entry
   %cmp2 = icmp ult ptr %a, %b
   br i1 %cmp2, label %if.then3, label %if.end12

 if.then3:                                         ; preds = %if.end
   %call4 = call ptr @ptr_sink_r0(ptr %b)
   %call5 = call ptr @ptr_scc_r1(ptr %a, ptr %b, ptr %r)
   %call6 = call ptr @ptr_scc_r2(ptr %r, ptr %r, ptr %r)
   %call7 = call ptr @ptr_scc_r1(ptr %a, ptr %call6, ptr %r)
   %call8 = call ptr @ptr_scc_r2(ptr %a, ptr %b, ptr %r)
   %call9 = call ptr @ptr_scc_r2(ptr %call5, ptr %call7, ptr %call8)
   %call10 = call ptr @ptr_scc_r1(ptr %a, ptr %b, ptr %r)
   %call11 = call ptr @ptr_scc_r1(ptr %call4, ptr %call9, ptr %call10)
   br label %return

 if.end12:                                         ; preds = %if.end
   %cmp13 = icmp eq ptr %a, %b
   br i1 %cmp13, label %cond.true, label %cond.false

 cond.true:                                        ; preds = %if.end12
   br label %cond.end

 cond.false:                                       ; preds = %if.end12
   %call14 = call ptr @ptr_scc_r2(ptr %a, ptr %b, ptr %r)
   br label %cond.end

 cond.end:                                         ; preds = %cond.false, %cond.true
   %cond = phi ptr [ %r, %cond.true ], [ %call14, %cond.false ]
   br label %return

 return:                                           ; preds = %cond.end, %if.then3, %if.then
   %retval.0 = phi ptr [ %call1, %if.then ], [ %call11, %if.then3 ], [ %cond, %cond.end ]
   ret ptr %retval.0
 }


 ; TEST a no-return singleton SCC
 ;
 ; int* rt0(int *a) {
 ;   return *a ? a : rt0(a);
 ; }
 ;
 ; FNATTR:  define ptr @rt0(ptr readonly %a)
 define ptr @rt0(ptr %a) #0 {
 entry:
   %v = load i32, ptr %a, align 4
   %tobool = icmp ne i32 %v, 0
   %call = call ptr @rt0(ptr %a)
   %sel = select i1 %tobool, ptr %a, ptr %call
   ret ptr %sel
 }

 ; TEST a no-return singleton SCC
 ;
 ; int* rt1(int *a) {
 ;   return *a ? undef : rt1(a);
 ; }
 ;
 ; FNATTR:  define noalias ptr @rt1(ptr nocapture readonly %a)
 define ptr @rt1(ptr %a) #0 {
 entry:
   %v = load i32, ptr %a, align 4
   %tobool = icmp ne i32 %v, 0
   %call = call ptr @rt1(ptr %a)
   %sel = select i1 %tobool, ptr undef, ptr %call
   ret ptr %sel
 }

 ; TEST another SCC test
 ;
 ; FNATTR:  define ptr @rt2_helper(ptr %a)
 ; FNATTR:  define ptr @rt2(ptr readnone %a, ptr readnone %b)
 define ptr @rt2_helper(ptr %a) #0 {
 entry:
   %call = call ptr @rt2(ptr %a, ptr %a)
   ret ptr %call
 }

 define ptr @rt2(ptr %a, ptr %b) #0 {
 entry:
   %cmp = icmp eq ptr %a, null
   br i1 %cmp, label %if.then, label %if.end

 if.then:
   %call = call ptr @rt2_helper(ptr %a)
   br label %if.end

 if.end:
   %sel = phi ptr [ %b, %entry], [%call, %if.then]
   ret ptr %sel
 }

 ; TEST another SCC test
 ;
 ; FNATTR:  define ptr @rt3_helper(ptr %a, ptr %b)
 ; FNATTR:  define ptr @rt3(ptr readnone %a, ptr readnone %b)
 define ptr @rt3_helper(ptr %a, ptr %b) #0 {
 entry:
   %call = call ptr @rt3(ptr %a, ptr %b)
   ret ptr %call
 }

 define ptr @rt3(ptr %a, ptr %b) #0 {
 entry:
   %cmp = icmp eq ptr %a, null
   br i1 %cmp, label %if.then, label %if.end

 if.then:
   %call = call ptr @rt3_helper(ptr %a, ptr %b)
   br label %if.end

 if.end:
   %sel = phi ptr [ %b, %entry], [%call, %if.then]
   ret ptr %sel
 }

 ; TEST address taken function with call to an external functions
 ;
 ;  void unknown_fn(ptr);
 ;
 ;  int* calls_unknown_fn(int *r) {
 ;    unknown_fn(&calls_unknown_fn);
 ;    return r;
 ;  }
 ;
 ;
 ; FNATTR:     define ptr @calls_unknown_fn(ptr readnone returned %r)
 declare void @unknown_fn(ptr) #0

 define ptr @calls_unknown_fn(ptr %r) #0 {
   tail call void @unknown_fn(ptr nonnull @calls_unknown_fn)
   ret ptr %r
 }


 ; TEST return call to a function that might be redifined at link time
 ;
 ;  int *maybe_redefined_fn2(int *r) {
 ;    return r;
 ;  }
 ;
 ;  int *calls_maybe_redefined_fn2(int *r) {
 ;    return maybe_redefined_fn2(r);
 ;  }
 ;
 ; Verify the maybe-redefined function is not annotated:
 ;
 ;
 ; FNATTR:     define ptr @calls_maybe_redefined_fn2(ptr %r)
 define linkonce_odr ptr @maybe_redefined_fn2(ptr %r) #0 {
 entry:
   ret ptr %r
 }

 define ptr @calls_maybe_redefined_fn2(ptr %r) #0 {
 entry:
   %call = call ptr @maybe_redefined_fn2(ptr %r)
   ret ptr %call
 }


 ; TEST returned argument goes through select and phi
 ;
 ; double select_and_phi(double b) {
 ;   double x = b;
 ;   if (b > 0)
 ;     x = b;
 ;   return b == 0? b : x;
 ; }
 ;
 ;
 ; FNATTR:     define double @select_and_phi(double %b)
 define double @select_and_phi(double %b) #0 {
 entry:
   %cmp = fcmp ogt double %b, 0.000000e+00
   br i1 %cmp, label %if.then, label %if.end

 if.then:                                          ; preds = %entry
   br label %if.end

 if.end:                                           ; preds = %if.then, %entry
   %phi = phi double [ %b, %if.then ], [ %b, %entry ]
   %cmp1 = fcmp oeq double %b, 0.000000e+00
   %sel = select i1 %cmp1, double %b, double %phi
   ret double %sel
 }


 ; TEST returned argument goes through recursion, select, and phi
 ;
 ; double recursion_select_and_phi(int a, double b) {
 ;   double x = b;
 ;   if (a-- > 0)
 ;     x = recursion_select_and_phi(a, b);
 ;   return b == 0? b : x;
 ; }
 ;
 ;
 ; FNATTR:     define double @recursion_select_and_phi(i32 %a, double %b)
 ;
 define double @recursion_select_and_phi(i32 %a, double %b) #0 {
 entry:
   %dec = add nsw i32 %a, -1
   %cmp = icmp sgt i32 %a, 0
   br i1 %cmp, label %if.then, label %if.end

 if.then:                                          ; preds = %entry
   %call = call double @recursion_select_and_phi(i32 %dec, double %b)
   br label %if.end

 if.end:                                           ; preds = %if.then, %entry
   %phi = phi double [ %call, %if.then ], [ %b, %entry ]
   %cmp1 = fcmp oeq double %b, 0.000000e+00
   %sel = select i1 %cmp1, double %b, double %phi
   ret double %sel
 }


 ; TEST returned argument goes through bitcasts
 ;
 ; ptr bitcast(int* b) {
 ;   return (ptr)b;
 ; }
 ;
 ;
 ; FNATTR:     define ptr @bitcast(ptr readnone returned %b)
 ;
 define ptr @bitcast(ptr %b) #0 {
 entry:
   ret ptr %b
 }


 ; TEST returned argument goes through select and phi interleaved with bitcasts
 ;
 ; ptr bitcasts_select_and_phi(int* b) {
 ;   ptr x = b;
 ;   if (b == 0)
 ;     x = b;
 ;   return b != 0 ? b : x;
 ; }
 ;
 ;
 ; FNATTR:     define ptr @bitcasts_select_and_phi(ptr readnone %b)
 ;
 define ptr @bitcasts_select_and_phi(ptr %b) #0 {
 entry:
   %cmp = icmp eq ptr %b, null
   br i1 %cmp, label %if.then, label %if.end

 if.then:                                          ; preds = %entry
   br label %if.end

 if.end:                                           ; preds = %if.then, %entry
   %phi = phi ptr [ %b, %if.then ], [ %b, %entry ]
   %cmp2 = icmp ne ptr %b, null
   %sel = select i1 %cmp2, ptr %phi, ptr %b
   ret ptr %sel
 }


 ; TEST return argument or argument or undef
 ;
 ; ptr ret_arg_arg_undef(int* b) {
 ;   if (b == 0)
 ;     return (ptr)b;
 ;   if (b == 0)
 ;     return (ptr)b;
 ;   /* return undef */
 ; }
 ;
 ;
 ; FNATTR:     define ptr @ret_arg_arg_undef(ptr readnone %b)
 ;
 define ptr @ret_arg_arg_undef(ptr %b) #0 {
 entry:
   %cmp = icmp eq ptr %b, null
   br i1 %cmp, label %ret_arg0, label %if.end

 ret_arg0:
   ret ptr %b

 if.end:
   br i1 %cmp, label %ret_arg1, label %ret_undef

 ret_arg1:
   ret ptr %b

 ret_undef:
   ret ptr undef
 }


 ; TEST return undef or argument or argument
 ;
 ; ptr ret_undef_arg_arg(int* b) {
 ;   if (b == 0)
 ;     return (ptr)b;
 ;   if (b == 0)
 ;     return (ptr)b;
 ;   /* return undef */
 ; }
 ;
 ;
 ; FNATTR:     define ptr @ret_undef_arg_arg(ptr readnone %b)
 ;
 define ptr @ret_undef_arg_arg(ptr %b) #0 {
 entry:
   %cmp = icmp eq ptr %b, null
   br i1 %cmp, label %ret_undef, label %if.end

 ret_undef:
   ret ptr undef

 if.end:
   br i1 %cmp, label %ret_arg0, label %ret_arg1

 ret_arg0:
   ret ptr %b

 ret_arg1:
   ret ptr %b
 }


 ; TEST return undef or argument or undef
 ;
 ; ptr ret_undef_arg_undef(int* b) {
 ;   if (b == 0)
 ;     /* return undef */
 ;   if (b == 0)
 ;     return (ptr)b;
 ;   /* return undef */
 ; }
 ;
 ;
 ; FNATTR:     define ptr @ret_undef_arg_undef(ptr readnone %b)
 define ptr @ret_undef_arg_undef(ptr %b) #0 {
 entry:
   %cmp = icmp eq ptr %b, null
   br i1 %cmp, label %ret_undef0, label %if.end

 ret_undef0:
   ret ptr undef

 if.end:
   br i1 %cmp, label %ret_arg, label %ret_undef1

 ret_arg:
   ret ptr %b

 ret_undef1:
   ret ptr undef
 }

 ; TEST return argument or unknown call result
 ;
 ; int* ret_arg_or_unknown(int* b) {
 ;   if (b == 0)
 ;     return b;
 ;   return unknown();
 ; }
 ;
 ; Verify we do not assume b is returned
 ;
 ; FNATTR:     define ptr @ret_arg_or_unknown(ptr %b)
 ; FNATTR:     define ptr @ret_arg_or_unknown_through_phi(ptr %b)
 declare ptr @unknown(ptr)

 define ptr @ret_arg_or_unknown(ptr %b) #0 {
 entry:
   %cmp = icmp eq ptr %b, null
   br i1 %cmp, label %ret_arg, label %ret_unknown

 ret_arg:
   ret ptr %b

 ret_unknown:
   %call = call ptr @unknown(ptr %b)
   ret ptr %call
 }

 define ptr @ret_arg_or_unknown_through_phi(ptr %b) #0 {
 entry:
   %cmp = icmp eq ptr %b, null
   br i1 %cmp, label %ret_arg, label %ret_unknown

 ret_arg:
   br label %r

 ret_unknown:
   %call = call ptr @unknown(ptr %b)
   br label %r

 r:
   %phi = phi ptr [ %b, %ret_arg ], [ %call, %ret_unknown ]
   ret ptr %phi
 }

 ; TEST inconsistent IR in dead code.
 ;
 ; FNATTR:     define i32 @deadblockcall1(i32 %A)
 ; FNATTR:     define i32 @deadblockcall2(i32 %A)
 ; FNATTR:     define i32 @deadblockphi1(i32 %A)
 ; FNATTR:     define i32 @deadblockphi2(i32 %A)
 define i32 @deadblockcall1(i32 %A) #0 {
 entry:
   ret i32 %A
 unreachableblock:
   %B = call i32 @deadblockcall1(i32 %B)
   ret i32 %B
 }

 declare i32 @deadblockcall_helper(i32 returned %A);

 define i32 @deadblockcall2(i32 %A) #0 {
 entry:
   ret i32 %A
 unreachableblock1:
   %B = call i32 @deadblockcall_helper(i32 %B)
   ret i32 %B
 unreachableblock2:
   %C = call i32 @deadblockcall1(i32 %C)
   ret i32 %C
 }

 define i32 @deadblockphi1(i32 %A) #0 {
 entry:
   br label %r
 unreachableblock1:
   %B = call i32 @deadblockcall_helper(i32 %B)
   ret i32 %B
 unreachableblock2:
   %C = call i32 @deadblockcall1(i32 %C)
   br label %r
 r:
   %PHI = phi i32 [%A, %entry], [%C, %unreachableblock2]
   ret i32 %PHI
 }

 define i32 @deadblockphi2(i32 %A) #0 {
 entry:
   br label %r
 unreachableblock1:
   %B = call i32 @deadblockcall_helper(i32 %B)
   br label %unreachableblock3
 unreachableblock2:
   %C = call i32 @deadblockcall1(i32 %C)
   br label %unreachableblock3
 unreachableblock3:
   %PHI1 = phi i32 [%B, %unreachableblock1], [%C, %unreachableblock2]
   br label %r
 r:
   %PHI2 = phi i32 [%A, %entry], [%PHI1, %unreachableblock3]
   ret i32 %PHI2
 }

 declare void @noreturn() noreturn;

 define i32 @deadblockphi3(i32 %A, i1 %c) #0 {
 entry:
   br i1 %c, label %r, label %unreachablecall
 unreachablecall:
   call void @noreturn();
   %B = call i32 @deadblockcall_helper(i32 0)
   br label %unreachableblock3
 unreachableblock2:
   %C = call i32 @deadblockcall1(i32 %C)
   br label %unreachableblock3
 unreachableblock3:
   %PHI1 = phi i32 [%B, %unreachablecall], [%C, %unreachableblock2]
   br label %r
 r:
   %PHI2 = phi i32 [%A, %entry], [%PHI1, %unreachableblock3]
   ret i32 %PHI2
 }

 attributes #0 = { noinline nounwind uwtable }
	; RUN: opt -passes=function-attrs -S < %s \| FileCheck %s --check-prefix=FNATTR
	;
	; Test cases specifically designed for the "returned" argument attribute.
	; We use FIXME's to indicate problems and missing attributes.
	;

	; TEST SCC test returning an integer value argument
	;
	;
	; FNATTR: define i32 @sink_r0(i32 returned %r)
	; FNATTR: define i32 @scc_r1(i32 %a, i32 %r, i32 %b)
	; FNATTR: define i32 @scc_r2(i32 %a, i32 %b, i32 %r)
	; FNATTR: define i32 @scc_rX(i32 %a, i32 %b, i32 %r)
	;
	;
	; int scc_r1(int a, int b, int r);
	; int scc_r2(int a, int b, int r);
	;
	; __attribute__((noinline)) int sink_r0(int r) {
	; return r;
	; }
	;
	; __attribute__((noinline)) int scc_r1(int a, int r, int b) {
	; return scc_r2(r, a, sink_r0(r));
	; }
	;
	; __attribute__((noinline)) int scc_r2(int a, int b, int r) {
	; if (a > b)
	; return scc_r2(b, a, sink_r0(r));
	; if (a < b)
	; return scc_r1(sink_r0(b), scc_r2(scc_r1(a, b, r), scc_r1(a, scc_r2(r, r, r), r), scc_r2(a, b, r)), scc_r1(a, b, r));
	; return a == b ? r : scc_r2(a, b, r);
	; }
	; __attribute__((noinline)) int scc_rX(int a, int b, int r) {
	; if (a > b)
	; return scc_r2(b, a, sink_r0(r));
	; if (a < b) // V Diff to scc_r2
	; return scc_r1(sink_r0(b), scc_r2(scc_r1(a, b, r), scc_r1(a, scc_r2(r, r, r), r), scc_r1(a, b, r)), scc_r1(a, b, r));
	; return a == b ? r : scc_r2(a, b, r);
	; }
	target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"

	define i32 @sink_r0(i32 %r) #0 {
	entry:
	ret i32 %r
	}

	define i32 @scc_r1(i32 %a, i32 %r, i32 %b) #0 {
	entry:
	%call = call i32 @sink_r0(i32 %r)
	%call1 = call i32 @scc_r2(i32 %r, i32 %a, i32 %call)
	ret i32 %call1
	}

	define i32 @scc_r2(i32 %a, i32 %b, i32 %r) #0 {
	entry:
	%cmp = icmp sgt i32 %a, %b
	br i1 %cmp, label %if.then, label %if.end

	if.then: ; preds = %entry
	%call = call i32 @sink_r0(i32 %r)
	%call1 = call i32 @scc_r2(i32 %b, i32 %a, i32 %call)
	br label %return

	if.end: ; preds = %entry
	%cmp2 = icmp slt i32 %a, %b
	br i1 %cmp2, label %if.then3, label %if.end12

	if.then3: ; preds = %if.end
	%call4 = call i32 @sink_r0(i32 %b)
	%call5 = call i32 @scc_r1(i32 %a, i32 %b, i32 %r)
	%call6 = call i32 @scc_r2(i32 %r, i32 %r, i32 %r)
	%call7 = call i32 @scc_r1(i32 %a, i32 %call6, i32 %r)
	%call8 = call i32 @scc_r2(i32 %a, i32 %b, i32 %r)
	%call9 = call i32 @scc_r2(i32 %call5, i32 %call7, i32 %call8)
	%call10 = call i32 @scc_r1(i32 %a, i32 %b, i32 %r)
	%call11 = call i32 @scc_r1(i32 %call4, i32 %call9, i32 %call10)
	br label %return

	if.end12: ; preds = %if.end
	%cmp13 = icmp eq i32 %a, %b
	br i1 %cmp13, label %cond.true, label %cond.false

	cond.true: ; preds = %if.end12
	br label %cond.end

	cond.false: ; preds = %if.end12
	%call14 = call i32 @scc_r2(i32 %a, i32 %b, i32 %r)
	br label %cond.end

	cond.end: ; preds = %cond.false, %cond.true
	%cond = phi i32 [ %r, %cond.true ], [ %call14, %cond.false ]
	br label %return

	return: ; preds = %cond.end, %if.then3, %if.then
	%retval.0 = phi i32 [ %call1, %if.then ], [ %call11, %if.then3 ], [ %cond, %cond.end ]
	ret i32 %retval.0
	}

	define i32 @scc_rX(i32 %a, i32 %b, i32 %r) #0 {
	entry:
	%cmp = icmp sgt i32 %a, %b
	br i1 %cmp, label %if.then, label %if.end

	if.then: ; preds = %entry
	%call = call i32 @sink_r0(i32 %r)
	%call1 = call i32 @scc_r2(i32 %b, i32 %a, i32 %call)
	br label %return

	if.end: ; preds = %entry
	%cmp2 = icmp slt i32 %a, %b
	br i1 %cmp2, label %if.then3, label %if.end12

	if.then3: ; preds = %if.end
	%call4 = call i32 @sink_r0(i32 %b)
	%call5 = call i32 @scc_r1(i32 %a, i32 %b, i32 %r)
	%call6 = call i32 @scc_r2(i32 %r, i32 %r, i32 %r)
	%call7 = call i32 @scc_r1(i32 %a, i32 %call6, i32 %r)
	%call8 = call i32 @scc_r1(i32 %a, i32 %b, i32 %r)
	%call9 = call i32 @scc_r2(i32 %call5, i32 %call7, i32 %call8)
	%call10 = call i32 @scc_r1(i32 %a, i32 %b, i32 %r)
	%call11 = call i32 @scc_r1(i32 %call4, i32 %call9, i32 %call10)
	br label %return

	if.end12: ; preds = %if.end
	%cmp13 = icmp eq i32 %a, %b
	br i1 %cmp13, label %cond.true, label %cond.false

	cond.true: ; preds = %if.end12
	br label %cond.end

	cond.false: ; preds = %if.end12
	%call14 = call i32 @scc_r2(i32 %a, i32 %b, i32 %r)
	br label %cond.end

	cond.end: ; preds = %cond.false, %cond.true
	%cond = phi i32 [ %r, %cond.true ], [ %call14, %cond.false ]
	br label %return

	return: ; preds = %cond.end, %if.then3, %if.then
	%retval.0 = phi i32 [ %call1, %if.then ], [ %call11, %if.then3 ], [ %cond, %cond.end ]
	ret i32 %retval.0
	}


	; TEST SCC test returning a pointer value argument
	;
	; FNATTR: define ptr @ptr_sink_r0(ptr readnone returned %r)
	; FNATTR: define ptr @ptr_scc_r1(ptr %a, ptr readnone %r, ptr nocapture readnone %b)
	; FNATTR: define ptr @ptr_scc_r2(ptr readnone %a, ptr readnone %b, ptr readnone %r)
	;
	;
	; ptr ptr_scc_r1(ptr a, ptr b, ptr r);
	; ptr ptr_scc_r2(ptr a, ptr b, ptr r);
	;
	; __attribute__((noinline)) ptr ptr_sink_r0(ptr r) {
	; return r;
	; }
	;
	; __attribute__((noinline)) ptr ptr_scc_r1(ptr a, ptr r, ptr b) {
	; return ptr_scc_r2(r, a, ptr_sink_r0(r));
	; }
	;
	; __attribute__((noinline)) ptr ptr_scc_r2(ptr a, ptr b, ptr r) {
	; if (a > b)
	; return ptr_scc_r2(b, a, ptr_sink_r0(r));
	; if (a < b)
	; return ptr_scc_r1(ptr_sink_r0(b), ptr_scc_r2(ptr_scc_r1(a, b, r), ptr_scc_r1(a, ptr_scc_r2(r, r, r), r), ptr_scc_r2(a, b, r)), ptr_scc_r1(a, b, r));
	; return a == b ? r : ptr_scc_r2(a, b, r);
	; }
	define ptr @ptr_sink_r0(ptr %r) #0 {
	entry:
	ret ptr %r
	}

	define ptr @ptr_scc_r1(ptr %a, ptr %r, ptr %b) #0 {
	entry:
	%call = call ptr @ptr_sink_r0(ptr %r)
	%call1 = call ptr @ptr_scc_r2(ptr %r, ptr %a, ptr %call)
	ret ptr %call1
	}

	define ptr @ptr_scc_r2(ptr %a, ptr %b, ptr %r) #0 {
	entry:
	%cmp = icmp ugt ptr %a, %b
	br i1 %cmp, label %if.then, label %if.end

	if.then: ; preds = %entry
	%call = call ptr @ptr_sink_r0(ptr %r)
	%call1 = call ptr @ptr_scc_r2(ptr %b, ptr %a, ptr %call)
	br label %return

	if.end: ; preds = %entry
	%cmp2 = icmp ult ptr %a, %b
	br i1 %cmp2, label %if.then3, label %if.end12

	if.then3: ; preds = %if.end
	%call4 = call ptr @ptr_sink_r0(ptr %b)
	%call5 = call ptr @ptr_scc_r1(ptr %a, ptr %b, ptr %r)
	%call6 = call ptr @ptr_scc_r2(ptr %r, ptr %r, ptr %r)
	%call7 = call ptr @ptr_scc_r1(ptr %a, ptr %call6, ptr %r)
	%call8 = call ptr @ptr_scc_r2(ptr %a, ptr %b, ptr %r)
	%call9 = call ptr @ptr_scc_r2(ptr %call5, ptr %call7, ptr %call8)
	%call10 = call ptr @ptr_scc_r1(ptr %a, ptr %b, ptr %r)
	%call11 = call ptr @ptr_scc_r1(ptr %call4, ptr %call9, ptr %call10)
	br label %return

	if.end12: ; preds = %if.end
	%cmp13 = icmp eq ptr %a, %b
	br i1 %cmp13, label %cond.true, label %cond.false

	cond.true: ; preds = %if.end12
	br label %cond.end

	cond.false: ; preds = %if.end12
	%call14 = call ptr @ptr_scc_r2(ptr %a, ptr %b, ptr %r)
	br label %cond.end

	cond.end: ; preds = %cond.false, %cond.true
	%cond = phi ptr [ %r, %cond.true ], [ %call14, %cond.false ]
	br label %return

	return: ; preds = %cond.end, %if.then3, %if.then
	%retval.0 = phi ptr [ %call1, %if.then ], [ %call11, %if.then3 ], [ %cond, %cond.end ]
	ret ptr %retval.0
	}


	; TEST a no-return singleton SCC
	;
	; int* rt0(int *a) {
	; return *a ? a : rt0(a);
	; }
	;
	; FNATTR: define ptr @rt0(ptr readonly %a)
	define ptr @rt0(ptr %a) #0 {
	entry:
	%v = load i32, ptr %a, align 4
	%tobool = icmp ne i32 %v, 0
	%call = call ptr @rt0(ptr %a)
	%sel = select i1 %tobool, ptr %a, ptr %call
	ret ptr %sel
	}

	; TEST a no-return singleton SCC
	;
	; int* rt1(int *a) {
	; return *a ? undef : rt1(a);
	; }
	;
	; FNATTR: define noalias ptr @rt1(ptr nocapture readonly %a)
	define ptr @rt1(ptr %a) #0 {
	entry:
	%v = load i32, ptr %a, align 4
	%tobool = icmp ne i32 %v, 0
	%call = call ptr @rt1(ptr %a)
	%sel = select i1 %tobool, ptr undef, ptr %call
	ret ptr %sel
	}

	; TEST another SCC test
	;
	; FNATTR: define ptr @rt2_helper(ptr %a)
	; FNATTR: define ptr @rt2(ptr readnone %a, ptr readnone %b)
	define ptr @rt2_helper(ptr %a) #0 {
	entry:
	%call = call ptr @rt2(ptr %a, ptr %a)
	ret ptr %call
	}

	define ptr @rt2(ptr %a, ptr %b) #0 {
	entry:
	%cmp = icmp eq ptr %a, null
	br i1 %cmp, label %if.then, label %if.end

	if.then:
	%call = call ptr @rt2_helper(ptr %a)
	br label %if.end

	if.end:
	%sel = phi ptr [ %b, %entry], [%call, %if.then]
	ret ptr %sel
	}

	; TEST another SCC test
	;
	; FNATTR: define ptr @rt3_helper(ptr %a, ptr %b)
	; FNATTR: define ptr @rt3(ptr readnone %a, ptr readnone %b)
	define ptr @rt3_helper(ptr %a, ptr %b) #0 {
	entry:
	%call = call ptr @rt3(ptr %a, ptr %b)
	ret ptr %call
	}

	define ptr @rt3(ptr %a, ptr %b) #0 {
	entry:
	%cmp = icmp eq ptr %a, null
	br i1 %cmp, label %if.then, label %if.end

	if.then:
	%call = call ptr @rt3_helper(ptr %a, ptr %b)
	br label %if.end

	if.end:
	%sel = phi ptr [ %b, %entry], [%call, %if.then]
	ret ptr %sel
	}

	; TEST address taken function with call to an external functions
	;
	; void unknown_fn(ptr);
	;
	; int* calls_unknown_fn(int *r) {
	; unknown_fn(&calls_unknown_fn);
	; return r;
	; }
	;
	;
	; FNATTR: define ptr @calls_unknown_fn(ptr readnone returned %r)
	declare void @unknown_fn(ptr) #0

	define ptr @calls_unknown_fn(ptr %r) #0 {
	tail call void @unknown_fn(ptr nonnull @calls_unknown_fn)
	ret ptr %r
	}


	; TEST return call to a function that might be redifined at link time
	;
	; int maybe_redefined_fn2(int r) {
	; return r;
	; }
	;
	; int calls_maybe_redefined_fn2(int r) {
	; return maybe_redefined_fn2(r);
	; }
	;
	; Verify the maybe-redefined function is not annotated:
	;
	;
	; FNATTR: define ptr @calls_maybe_redefined_fn2(ptr %r)
	define linkonce_odr ptr @maybe_redefined_fn2(ptr %r) #0 {
	entry:
	ret ptr %r
	}

	define ptr @calls_maybe_redefined_fn2(ptr %r) #0 {
	entry:
	%call = call ptr @maybe_redefined_fn2(ptr %r)
	ret ptr %call
	}


	; TEST returned argument goes through select and phi
	;
	; double select_and_phi(double b) {
	; double x = b;
	; if (b > 0)
	; x = b;
	; return b == 0? b : x;
	; }
	;
	;
	; FNATTR: define double @select_and_phi(double %b)
	define double @select_and_phi(double %b) #0 {
	entry:
	%cmp = fcmp ogt double %b, 0.000000e+00
	br i1 %cmp, label %if.then, label %if.end

	if.then: ; preds = %entry
	br label %if.end

	if.end: ; preds = %if.then, %entry
	%phi = phi double [ %b, %if.then ], [ %b, %entry ]
	%cmp1 = fcmp oeq double %b, 0.000000e+00
	%sel = select i1 %cmp1, double %b, double %phi
	ret double %sel
	}


	; TEST returned argument goes through recursion, select, and phi
	;
	; double recursion_select_and_phi(int a, double b) {
	; double x = b;
	; if (a-- > 0)
	; x = recursion_select_and_phi(a, b);
	; return b == 0? b : x;
	; }
	;
	;
	; FNATTR: define double @recursion_select_and_phi(i32 %a, double %b)
	;
	define double @recursion_select_and_phi(i32 %a, double %b) #0 {
	entry:
	%dec = add nsw i32 %a, -1
	%cmp = icmp sgt i32 %a, 0
	br i1 %cmp, label %if.then, label %if.end

	if.then: ; preds = %entry
	%call = call double @recursion_select_and_phi(i32 %dec, double %b)
	br label %if.end

	if.end: ; preds = %if.then, %entry
	%phi = phi double [ %call, %if.then ], [ %b, %entry ]
	%cmp1 = fcmp oeq double %b, 0.000000e+00
	%sel = select i1 %cmp1, double %b, double %phi
	ret double %sel
	}


	; TEST returned argument goes through bitcasts
	;
	; ptr bitcast(int* b) {
	; return (ptr)b;
	; }
	;
	;
	; FNATTR: define ptr @bitcast(ptr readnone returned %b)
	;
	define ptr @bitcast(ptr %b) #0 {
	entry:
	ret ptr %b
	}


	; TEST returned argument goes through select and phi interleaved with bitcasts
	;
	; ptr bitcasts_select_and_phi(int* b) {
	; ptr x = b;
	; if (b == 0)
	; x = b;
	; return b != 0 ? b : x;
	; }
	;
	;
	; FNATTR: define ptr @bitcasts_select_and_phi(ptr readnone %b)
	;
	define ptr @bitcasts_select_and_phi(ptr %b) #0 {
	entry:
	%cmp = icmp eq ptr %b, null
	br i1 %cmp, label %if.then, label %if.end

	if.then: ; preds = %entry
	br label %if.end

	if.end: ; preds = %if.then, %entry
	%phi = phi ptr [ %b, %if.then ], [ %b, %entry ]
	%cmp2 = icmp ne ptr %b, null
	%sel = select i1 %cmp2, ptr %phi, ptr %b
	ret ptr %sel
	}


	; TEST return argument or argument or undef
	;
	; ptr ret_arg_arg_undef(int* b) {
	; if (b == 0)
	; return (ptr)b;
	; if (b == 0)
	; return (ptr)b;
	; /* return undef */
	; }
	;
	;
	; FNATTR: define ptr @ret_arg_arg_undef(ptr readnone %b)
	;
	define ptr @ret_arg_arg_undef(ptr %b) #0 {
	entry:
	%cmp = icmp eq ptr %b, null
	br i1 %cmp, label %ret_arg0, label %if.end

	ret_arg0:
	ret ptr %b

	if.end:
	br i1 %cmp, label %ret_arg1, label %ret_undef

	ret_arg1:
	ret ptr %b

	ret_undef:
	ret ptr undef
	}


	; TEST return undef or argument or argument
	;
	; ptr ret_undef_arg_arg(int* b) {
	; if (b == 0)
	; return (ptr)b;
	; if (b == 0)
	; return (ptr)b;
	; /* return undef */
	; }
	;
	;
	; FNATTR: define ptr @ret_undef_arg_arg(ptr readnone %b)
	;
	define ptr @ret_undef_arg_arg(ptr %b) #0 {
	entry:
	%cmp = icmp eq ptr %b, null
	br i1 %cmp, label %ret_undef, label %if.end

	ret_undef:
	ret ptr undef

	if.end:
	br i1 %cmp, label %ret_arg0, label %ret_arg1

	ret_arg0:
	ret ptr %b

	ret_arg1:
	ret ptr %b
	}


	; TEST return undef or argument or undef
	;
	; ptr ret_undef_arg_undef(int* b) {
	; if (b == 0)
	; /* return undef */
	; if (b == 0)
	; return (ptr)b;
	; /* return undef */
	; }
	;
	;
	; FNATTR: define ptr @ret_undef_arg_undef(ptr readnone %b)
	define ptr @ret_undef_arg_undef(ptr %b) #0 {
	entry:
	%cmp = icmp eq ptr %b, null
	br i1 %cmp, label %ret_undef0, label %if.end

	ret_undef0:
	ret ptr undef

	if.end:
	br i1 %cmp, label %ret_arg, label %ret_undef1

	ret_arg:
	ret ptr %b

	ret_undef1:
	ret ptr undef
	}

	; TEST return argument or unknown call result
	;
	; int* ret_arg_or_unknown(int* b) {
	; if (b == 0)
	; return b;
	; return unknown();
	; }
	;
	; Verify we do not assume b is returned
	;
	; FNATTR: define ptr @ret_arg_or_unknown(ptr %b)
	; FNATTR: define ptr @ret_arg_or_unknown_through_phi(ptr %b)
	declare ptr @unknown(ptr)

	define ptr @ret_arg_or_unknown(ptr %b) #0 {
	entry:
	%cmp = icmp eq ptr %b, null
	br i1 %cmp, label %ret_arg, label %ret_unknown

	ret_arg:
	ret ptr %b

	ret_unknown:
	%call = call ptr @unknown(ptr %b)
	ret ptr %call
	}

	define ptr @ret_arg_or_unknown_through_phi(ptr %b) #0 {
	entry:
	%cmp = icmp eq ptr %b, null
	br i1 %cmp, label %ret_arg, label %ret_unknown

	ret_arg:
	br label %r

	ret_unknown:
	%call = call ptr @unknown(ptr %b)
	br label %r

	r:
	%phi = phi ptr [ %b, %ret_arg ], [ %call, %ret_unknown ]
	ret ptr %phi
	}

	; TEST inconsistent IR in dead code.
	;
	; FNATTR: define i32 @deadblockcall1(i32 %A)
	; FNATTR: define i32 @deadblockcall2(i32 %A)
	; FNATTR: define i32 @deadblockphi1(i32 %A)
	; FNATTR: define i32 @deadblockphi2(i32 %A)
	define i32 @deadblockcall1(i32 %A) #0 {
	entry:
	ret i32 %A
	unreachableblock:
	%B = call i32 @deadblockcall1(i32 %B)
	ret i32 %B
	}

	declare i32 @deadblockcall_helper(i32 returned %A);

	define i32 @deadblockcall2(i32 %A) #0 {
	entry:
	ret i32 %A
	unreachableblock1:
	%B = call i32 @deadblockcall_helper(i32 %B)
	ret i32 %B
	unreachableblock2:
	%C = call i32 @deadblockcall1(i32 %C)
	ret i32 %C
	}

	define i32 @deadblockphi1(i32 %A) #0 {
	entry:
	br label %r
	unreachableblock1:
	%B = call i32 @deadblockcall_helper(i32 %B)
	ret i32 %B
	unreachableblock2:
	%C = call i32 @deadblockcall1(i32 %C)
	br label %r
	r:
	%PHI = phi i32 [%A, %entry], [%C, %unreachableblock2]
	ret i32 %PHI
	}

	define i32 @deadblockphi2(i32 %A) #0 {
	entry:
	br label %r
	unreachableblock1:
	%B = call i32 @deadblockcall_helper(i32 %B)
	br label %unreachableblock3
	unreachableblock2:
	%C = call i32 @deadblockcall1(i32 %C)
	br label %unreachableblock3
	unreachableblock3:
	%PHI1 = phi i32 [%B, %unreachableblock1], [%C, %unreachableblock2]
	br label %r
	r:
	%PHI2 = phi i32 [%A, %entry], [%PHI1, %unreachableblock3]
	ret i32 %PHI2
	}

	declare void @noreturn() noreturn;

	define i32 @deadblockphi3(i32 %A, i1 %c) #0 {
	entry:
	br i1 %c, label %r, label %unreachablecall
	unreachablecall:
	call void @noreturn();
	%B = call i32 @deadblockcall_helper(i32 0)
	br label %unreachableblock3
	unreachableblock2:
	%C = call i32 @deadblockcall1(i32 %C)
	br label %unreachableblock3
	unreachableblock3:
	%PHI1 = phi i32 [%B, %unreachablecall], [%C, %unreachableblock2]
	br label %r
	r:
	%PHI2 = phi i32 [%A, %entry], [%PHI1, %unreachableblock3]
	ret i32 %PHI2
	}

	attributes #0 = { noinline nounwind uwtable }