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; RUN: opt -S -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 < %s | FileCheck %s
; CHECK-LABEL: @speculatable_attribute
; CHECK: select
define i32 @speculatable_attribute(i32 %a) {
entry:
%c = icmp sgt i32 %a, 64
br i1 %c, label %end, label %if
if:
%val = call i32 @func() #0
br label %end
end:
%ret = phi i32 [%val, %if], [0, %entry]
ret i32 %ret
}
define i32 @func() #0 {
ret i32 1
}
; We should correctly drop the attribute since it may no longer be valid
; in the context the call is moved to.
; Since the function is speculatable, the nonnull attribute need not be dropped
; since it propagates poison (and call executes fine) if the parameter is indeed
; null.
define i32 @strip_attr(ptr %p) {
; CHECK-LABEL: strip_attr
; CHECK-LABEL: entry:
; CHECK: %nullchk = icmp ne ptr %p, null
; CHECK: %val = call i32 @func_nonnull(ptr nonnull %p)
; CHECK: select
entry:
%nullchk = icmp ne ptr %p, null
br i1 %nullchk, label %if, label %end
if:
%val = call i32 @func_nonnull(ptr nonnull %p) #1
br label %end
end:
%ret = phi i32 [%val, %if], [0, %entry]
ret i32 %ret
}
; We should strip the deref attribute since it can cause UB when the
; speculatable call is moved.
define i32 @strip_attr2(ptr %p) {
; CHECK-LABEL: strip_attr2
; CHECK-LABEL: entry:
; CHECK: %nullchk = icmp ne ptr %p, null
; CHECK: %val = call i32 @func_nonnull(ptr %p)
; CHECK: select
entry:
%nullchk = icmp ne ptr %p, null
br i1 %nullchk, label %if, label %end
if:
%val = call i32 @func_nonnull(ptr dereferenceable(12) %p) #1
br label %end
end:
%ret = phi i32 [%val, %if], [0, %entry]
ret i32 %ret
}
declare i32 @func_nonnull(ptr) #1
attributes #0 = { nounwind readnone speculatable }
attributes #1 = { nounwind argmemonly speculatable }
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