[PATCH 1/5 v1] LoongArch: bfd: Add new reloc types.

[Xi Ruoyao]

On Mon, 2022-07-18 at 18:06 +0800, WANG Xuerui wrote:
> (Adding Ruoyao and MaskRay to CC, who might be interested in this 
> development as well, as it concerns the linker implementation.)

I've already subscribed binutils@sourceware.org in order not to be
passed by.

> I think I've voiced my concerns over the naming of these ops multiple 
> times already; the primary comment ([1]; in English) was posted back in 
> May but no one in your team responded.
> 
> Reproducing the content (and adjusting a little) here:
> 
> 
> Overall in a good direction (and IMHO the direction everyone should have 
> taken in the first place), thanks!
> 

Yes, we've been paying additional costs using those "stack based
relocation".  I'd like to know why they were proposed in first place? 
(Not accusing anyone, just my curiosity: AFAIK no other targets ever
used such a stack for relocation.)

/* snip */


> FYI, I did make a list of my suggested names for these reloc types 
> ("BFD_RELOC_LARCH_" abbreviated to "B_R_L_"):
> 
> Original name           Suggested name
> -------------           --------------
> B_R_L_B16               B_R_L_PCREL_SK16 *1
> B_R_L_B21               B_R_L_PCREL_SD5K16
> B_R_L_B26               B_R_L_PCREL_SD10K16
> B_R_L_ABS_LO12          B_R_L_ABS_0_SK12
> B_R_L_ABS_HI20          B_R_L_ABS_12_SJ20
> B_R_L_ABS64_LO20        B_R_L_ABS_32_SJ20
> B_R_L_ABS64_HI12        B_R_L_ABS_52_SK12
> B_R_L_PCALA_LO12        B_R_L_PCALA_0_SK12 *2
> B_R_L_PCALA_HI20        B_R_L_PCALA_12_SJ20
> B_R_L_PCALA64_LO20      B_R_L_PCALA_32_SJ20 *3
> B_R_L_PCALA64_HI12      B_R_L_PCALA_52_SK12
> B_R_L_GOT_PC_LO12       B_R_L_GOT_PCALA_0_SK12 *4
> B_R_L_GOT_PC_HI20       B_R_L_GOT_PCALA_12_SJ20
> B_R_L_GOT64_PC_LO20     B_R_L_GOT_PCALA_32_SJ20
> B_R_L_GOT64_PC_HI12     B_R_L_GOT_PCALA_52_SK12
> B_R_L_GOT64_LO12        B_R_L_GOT_ABS_0_SK12 *5
> B_R_L_GOT64_HI20        B_R_L_GOT_ABS_12_SJ20
> B_R_L_GOT64_LO20        B_R_L_GOT_ABS_32_SJ20
> B_R_L_GOT64_HI12        B_R_L_GOT_ABS_52_SK12
> B_R_L_TLS_LE_LO12       B_R_L_TLS_LE_ABS_0_SK12
> B_R_L_TLS_LE_HI20       B_R_L_TLS_LE_ABS_12_SJ20
> B_R_L_TLS_LE64_LO20     B_R_L_TLS_LE_ABS_32_SJ20
> B_R_L_TLS_LE64_HI12     B_R_L_TLS_LE_ABS_52_SK12
> B_R_L_TLS_IE_PC_LO12    B_R_L_TLS_IE_PCALA_0_SK12
> B_R_L_TLS_IE_PC_HI20    B_R_L_TLS_IE_PCALA_12_SJ20
> B_R_L_TLS_IE64_PC_LO20  B_R_L_TLS_IE_PCALA_32_SJ20
> B_R_L_TLS_IE64_PC_HI12  B_R_L_TLS_IE_PCALA_52_SK12
> B_R_L_TLS_IE64_LO12     B_R_L_TLS_IE_ABS_0_SK12
> B_R_L_TLS_IE64_HI20     B_R_L_TLS_IE_ABS_12_SJ20
> B_R_L_TLS_IE64_LO20     B_R_L_TLS_IE_ABS_32_SJ20
> B_R_L_TLS_IE64_HI12     B_R_L_TLS_IE_ABS_52_SK12
> B_R_L_TLS_LD_PC_HI20    B_R_L_TLS_LD_PCALA_12_SJ20 *6
> B_R_L_TLS_LD64_HI20     B_R_L_TLS_LD_ABS_12_SJ20
> B_R_L_TLS_GD_PC_HI20    B_R_L_TLS_GD_PCALA_12_SJ20
> B_R_L_TLS_GD64_HI20     B_R_L_TLS_GD_ABS_12_SJ20

It's overall better, but those "J, K" etc are cryptic IMHO.  And for
"B_R_L_B16" I think "B_R_L_PCREL_SK16" fails to express that the offset
should be shifted right by 2, so I'd keep B_R_L_B16 (and similarly,
B_R_L_B21 and B_R_L_B26) like the PCALA case.

-- 
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University