c/7344: performance regression on huge case statements

[Robert Schiele]

On Thu, Oct 17, 2002 at 08:59:26AM -0400, Nathanael Nerode wrote:
> What should we do for a test case here?  I feel that it should have one,
> but the minimal testcase is *inherently* 239K, so I'm not quite sure 
> what to do here.

Hmm, we can do this testcase with the following short code:

---
#define CL0(a) case a: f(); goto c;
#define CL1(a) CL0(a##0) CL0(a##1) CL0(a##2) CL0(a##3) CL0(a##4) CL0(a##5) CL0(a##6) CL0(a##7) CL0(a##8) CL0(a##9)
#define CL2(a) CL1(a##0) CL1(a##1) CL1(a##2) CL1(a##3) CL1(a##4) CL1(a##5) CL1(a##6) CL1(a##7) CL1(a##8) CL1(a##9)
#define CL3(a) CL2(a##0) CL2(a##1) CL2(a##2) CL2(a##3) CL2(a##4) CL2(a##5) CL2(a##6) CL2(a##7) CL2(a##8) CL2(a##9)
#define CL4(a) CL3(a##0) CL3(a##1) CL3(a##2) CL3(a##3) CL3(a##4) CL3(a##5) CL3(a##6) CL3(a##7) CL3(a##8) CL3(a##9)

void f();

void a() {
    int b;
 c: switch (b) {
        CL4(1)
    }
}
---

Robert

-- 
Robert Schiele			Tel.: +49-621-181-2517
Dipl.-Wirtsch.informatiker	mailto:rschiele@uni-mannheim.de
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