Hi
I found llvm Sink.cpp pass has a bug. Running opt -basicaa -sink
diamond.ll moves the load in entry BB to BBX. This is incorrect as
there is a store in BB0.
It seems Sink pass is not enabled in the O3 pipeline, Is this the
reason why it is disabled ?
Also, I see sink can not handle sinking across loop either.
*** IR Dump Before Code sinking ***
define i32 @diamond(i32 %a, i32 %b, i32 %c, i32* dereferenceable(32) %d) {
%1 = mul nsw i32 %c, %b
%2 = load i32, i32* %d
%3 = icmp sgt i32 %a, 0
br i1 %3, label %B0, label %B1
B0: ; preds = %0
store i32 0, i32* %d
br label %X
B1: ; preds = %0
br label %X
X: ; preds = %B1, %B0
%R = sub i32 %1, %2
ret i32 %R
}
*** IR Dump Before Module Verifier ***
define i32 @diamond(i32 %a, i32 %b, i32 %c, i32* dereferenceable(32) %d) {
%1 = icmp sgt i32 %a, 0
br i1 %1, label %B0, label %B1
B0: ; preds = %0
store i32 0, i32* %d
br label %X
B1: ; preds = %0
br label %X
X: ; preds = %B1, %B0
%2 = mul nsw i32 %c, %b
%3 = load i32, i32* %d
%R = sub i32 %2, %3
ret i32 %R
}
Thanks
-Xin