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<div>Hi Mehdi</div><div>I want to know <span style="background-color: transparent; line-height: 1.5;"> how to generate the IR ,that do not use the ¡°main.a¡± global constant variable, and llvm.memcpy intrinsic , instead of liking other local variable initialization :</span></div><div><span style="background-color: transparent; line-height: 1.5;"> </span><span style="background-color: transparent; line-height: 1.5;"> </span><span style="color: rgb(0, 0, 0); background-color: transparent; line-height: 1.5;">store i32 7, i32* %b, align 4</span></div><div><span style="color: rgb(0, 0, 0); background-color: transparent; line-height: 1.5;"> For example :</span></div><div><span style="color: rgb(0, 0, 0); background-color: transparent; line-height: 1.5;"> %element0 = </span><span style="background-color: transparent; line-height: 1.5;">getelementptr inbounds [3 x i32]* %a, i32 0, i32 0</span></div><div><span style="background-color: transparent; line-height: 1.5;"> store i32 1, i32* %element0, align 4</span></div><div><span style="background-color: transparent; line-height: 1.5;"> </span><span style="color: rgb(0, 0, 0); background-color: transparent; line-height: 1.5;"> %element1 = </span><span style="background-color: transparent; line-height: 1.5;">getelementptr inbounds [3 x i32]* %a, i32 0, i32 1</span></div><div><span style="background-color: transparent; line-height: 1.5;"> store i32 2, i32* %element1, align 4</span></div><div><span style="background-color: transparent; line-height: 1.5;">Thank you</span></div><div><span style="background-color: transparent; font-size: 10.5pt; line-height: 1.5;"> </span></div><blockquote style="margin-top: 0px; margin-bottom: 0px; margin-left: 0.5em;"><div><div> </div>
<div>> On Dec 27, 2016, at 11:09 PM, liuyu11@ict.ac.cn via llvm-dev <llvm-dev@lists.llvm.org> wrote:</div>
<div>> </div>
<div>> Hello,everyone:</div>
<div>> I want to known how to let clang compile my local array to local variables:</div>
<div>> I have the code :</div>
<div>> int main()</div>
<div>> {</div>
<div>> int a[3]={1,2,3};</div>
<div>> </div>
<div>> int b=7;</div>
<div>> int c=8;</div>
<div>> int d=9;</div>
<div>> int e=10;</div>
<div>> int f=11;</div>
<div>> test(b,c,d,e,f,a);</div>
<div>> return 0;</div>
<div>> }</div>
<div>> I use clang command:clang --target=mipsel -emit-llvm -S a.c -o a.ll</div>
<div>> The a.ll is:</div>
<div>> @main.a = private unnamed_addr constant [3 x i32] [i32 1, i32 2, i32 3], align 4</div>
<div>> define i32 @main() #0 {</div>
<div>> entry:</div>
<div>> %retval = alloca i32, align 4</div>
<div>> %a = alloca [3 x i32], align 4</div>
<div>> %b = alloca i32, align 4</div>
<div>> %c = alloca i32, align 4</div>
<div>> %d = alloca i32, align 4</div>
<div>> %e = alloca i32, align 4</div>
<div>> %f = alloca i32, align 4</div>
<div>> store i32 0, i32* %retval</div>
<div>> %0 = bitcast [3 x i32]* %a to i8*</div>
<div>> call void @llvm.memcpy.p0i8.p0i8.i32(i8* %0, i8* bitcast ([3 x i32]* @main.a to i8*), i32 12, i32 4, i1 false)</div>
<div>> store i32 7, i32* %b, align 4</div>
<div>> store i32 8, i32* %c, align 4</div>
<div>> store i32 9, i32* %d, align 4</div>
<div>> store i32 10, i32* %e, align 4</div>
<div>> store i32 11, i32* %f, align 4</div>
<div>> %1 = load i32, i32* %b, align 4</div>
<div>> %2 = load i32, i32* %c, align 4</div>
<div>> %3 = load i32, i32* %d, align 4</div>
<div>> %4 = load i32, i32* %e, align 4</div>
<div>> %5 = load i32, i32* %f, align 4</div>
<div>> %arraydecay = getelementptr inbounds [3 x i32], [3 x i32]* %a, i32 0, i32 0</div>
<div>> call void @test(i32 signext %1, i32 signext %2, i32 signext %3, i32 signext %4, i32 signext %5, i32* %arraydecay)</div>
<div>> ret i32 0;}</div>
<div>> I want to known how to compile local array a to a local variable</div>
<div> </div>
<div>Your question is not totally clear: a *is* a ¡°local variable¡± on the stack, this is the line:</div>
<div> </div>
<div>> %a = alloca [3 x i32], align 4</div>
<div> </div>
<div>It is initialized here:</div>
<div> </div>
<div>> call void @llvm.memcpy.p0i8.p0i8.i32(i8* %0, i8* bitcast ([3 x i32]* @main.a to i8*), i32 12, i32 4, i1 false)</div>
<div> </div>
<div>using the constant data that is stored in a global:</div>
<div> </div>
<div>> @main.a = private unnamed_addr constant [3 x i32] [i32 1, i32 2, i32 3], align 4</div>
<div> </div>
<div>What would you like the code to look like?</div>
<div> </div>
<div>¡ª </div>
<div>Mehdi</div>
<div> </div>
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