Do C++ compilers eliminate assignment duplications?

If I have an example function like:

void func1(float a, float b, float c)
{
    setA(a);
    setB(b);
    setC(c);                                        
}

Which calls inlined functions:

inline void setA(float a){ m_a = a; m_isValid = false; }
inline void setB(float b){ m_b = b; m_isValid = false; }
inline void setC(float c){ m_c = c; m_isValid = false; }

Should I care about the "m_isValid = false" duplications or the compiler eliminates them by the optimization?

A decent compiler should remove them in this specific case.

Completing to a full compiling example

struct Foo {
    float m_a, m_b, m_c;
    bool m_isValid;

    void setA(float a){ m_a = a; m_isValid = false; }
    void setB(float b){ m_b = b; m_isValid = false; }
    void setC(float c){ m_c = c; m_isValid = false; }

    void func1(float a, float b, float c);
};

Foo f;

void func1(float a, float b, float c)
{
    f.setA(a);
    f.setB(b);
    f.setC(c);
}

g++ in this case compiles func1 to

_Z5func1fff:
.LFB3:
    .cfi_startproc
    movl    4(%esp), %eax     ;; loads a
    movb    $0, f+12          ;; clears m_isValid
    movl    %eax, f           ;; stores m_a
    movl    8(%esp), %eax     ;; loads b
    movl    %eax, f+4         ;; stores m_b
    movl    12(%esp), %eax    ;; loads c
    movl    %eax, f+8         ;; stores m_c
    ret
    .cfi_endproc

Note that while it's true that you should keep an eye out about how to design a program if performance is an issue, this kind of micro-level optimization is best done at the end, after measuring where the code is actually losing time.