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