Re: [PATCH 2/3] powerpc/module32: Use symbolic instructions names.

Le 29/04/2019 à 13:54, Segher Boessenkool a écrit :

On Mon, Apr 29, 2019 at 10:43:27AM +0000, Christophe Leroy wrote:

quoted

To increase readability/maintainability, replace hard coded
instructions values by symbolic names.

quoted

+	/* lis r12,sym@ha */
+#define ENTRY_JMP0(sym)	(PPC_INST_ADDIS | __PPC_RT(R12) | PPC_HA(sym))
+	/* addi r12,r12,sym@l */
+#define ENTRY_JMP1(sym)	(PPC_INST_ADDI | __PPC_RT(R12) | __PPC_RA(R12) | PPC_LO(sym))

Those aren't "jump" instructions though, as the name suggests...  And you
only have names for the first two of the four insns.  ("2" and "3" were
still available ;-) )

Well, the idea was to say they are defining the jump destination.
Anyway, as they are used only once, let's put it directly in.

quoted

-	entry->jump[0] = 0x3d800000+((val+0x8000)>>16); /* lis r12,sym@ha */
-	entry->jump[1] = 0x398c0000 + (val&0xffff);     /* addi r12,r12,sym@l*/
-	entry->jump[2] = 0x7d8903a6;                    /* mtctr r12 */
-	entry->jump[3] = 0x4e800420;			/* bctr */
+	entry->jump[0] = ENTRY_JMP0(val);
+	entry->jump[1] = ENTRY_JMP1(val);
+	entry->jump[2] = PPC_INST_MTCTR | __PPC_RS(R12);
+	entry->jump[3] = PPC_INST_BCTR;

Deleting the comment here is not an improvement imo.

Ok, I'll leave them in as I did for module64

Christophe

Segher