[LLVMdev] floor

[Reed Kotler]

Here is a test case:

extern double floor(double);
extern double floor_(double);

double x = 1.5;
double y, y_;

void foo() {

   double y = floor(x);
   double y_ = floor_(x);
}


If I compile this for Mips16, it calls the proper helper function for 
floor_ but not for floor, because the signature for floor in callee info 
is wrong. Args[0] = void RetTy = void

/local/llvmpb_config/install/bin/clang -target mipsel-linux-gnu floor1.c 
-o floor1.s -mips16 -S -fPIC

.....
	lw	$3, %got(x)($2)
	lw	$4, 0($3)
	lw	$5, 4($3)
	lw	$6, %call16(floor)($2)
	move	$25, $6
	move	$gp, $2
	sw	$2, 20 ( $16 );
	sw	$3, 16 ( $16 );
	jalrc 	$6
	sw	$3, 36($16)
	sw	$2, 32($16)
	lw	$2, 16 ( $16 );
	lw	$5, 4($2)
	lw	$4, 0($2)
	lw	$3, 20 ( $16 );
	lw	$2, %call16(floor_)($3)
	lw	$6, %got(__mips16_call_stub_df_2)($3)
	move	$gp, $3
	jalrc 	$6

....


On 07/26/2013 03:33 PM, reed kotler wrote:
> I'm getting some problems because it seems that the compiler is treating
> "floor" differently from other math library functions like "sin".
>
> The Args and RetVal have the parameter and return types marked as void.
>
> For mips16, it's important that I be able to know the original signature
> for floating point functions.
>
> In some cases, need to create calls to helper functions based on the
> signatures.
>
> In newer code I've written, I've actually moved this logica to an IR
> pass and in that case I know for sure.
>
> But this part of the code is in ISelLowering code and I rely on getting
> the proper signature information.
>
> I'm looking at llvm now to see how this is occurring but maybe someone
> just knows.
>
> Tia.
>
> Reed