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8573384010
When if converting something like: true: ... = R0<kill> false: ... = R0<kill> then the instructions of the true block must not have a <kill> flag anymore, as the instruction of the false block follow and do still read the R0 value. Specifically this patch determines the set of register live-in in the false block (possibly after simulating the liveness changes of the duplicated instructions). Each of these live-in registers mustn't be killed. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192482 91177308-0d34-0410-b5e6-96231b3b80d8
31 lines
877 B
LLVM
31 lines
877 B
LLVM
; RUN: llc < %s -march arm -mcpu swift -verify-machineinstrs
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declare i32 @f(i32 %p0, i32 %p1)
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define i32 @foo(i32* %ptr) {
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entry:
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%cmp = icmp ne i32* %ptr, null
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br i1 %cmp, label %if.then, label %if.else
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; present something which can be easily if-converted
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if.then:
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; %R0 should be killed here
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%valt = load i32* %ptr, align 4
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br label %return
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if.else:
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; %R0 should be killed here, however after if-conversion the %R0 kill
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; has to be removed because if.then will follow after this and still
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; read it.
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%addr = getelementptr inbounds i32* %ptr, i32 4
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%vale = load i32* %addr, align 4
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br label %return
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return:
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%phival = phi i32 [ %valt, %if.then ], [ %vale, %if.else ]
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; suggest to bring %phival/%valt/%vale into %R1 (because otherwise there
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; will be no kills in if.then/if.else)
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%retval = call i32 @f (i32 0, i32 %phival)
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ret i32 %retval
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}
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