diff mbox series

[v3,07/17] powerpc: Don't update CR0 in emulation of popcnt, prty, bpermd instructions

Message ID 1504066360-30128-8-git-send-email-paulus@ozlabs.org (mailing list archive)
State Accepted
Commit 5762e08344bd7c5bfc41030f74c4ab6ce6e461d0
Headers show
Series powerpc: Do alignment fixups using analyse_instr etc. | expand

Commit Message

Paul Mackerras Aug. 30, 2017, 4:12 a.m. UTC 
The architecture shows the least-significant bit of the instruction
word as reserved for the popcnt[bwd], prty[wd] and bpermd
instructions, that is, these instructions never update CR0.
Therefore this changes the emulation of these instructions to
skip the CR0 update.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
---
 arch/powerpc/lib/sstep.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 522bc7b..114e597 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -1469,7 +1469,7 @@  int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 
 		case 122:	/* popcntb */
 			do_popcnt(regs, op, regs->gpr[rd], 8);
-			goto logical_done;
+			goto logical_done_nocc;
 
 		case 124:	/* nor */
 			op->val = ~(regs->gpr[rd] | regs->gpr[rb]);
@@ -1477,15 +1477,15 @@  int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 
 		case 154:	/* prtyw */
 			do_prty(regs, op, regs->gpr[rd], 32);
-			goto logical_done;
+			goto logical_done_nocc;
 
 		case 186:	/* prtyd */
 			do_prty(regs, op, regs->gpr[rd], 64);
-			goto logical_done;
+			goto logical_done_nocc;
 #ifdef CONFIG_PPC64
 		case 252:	/* bpermd */
 			do_bpermd(regs, op, regs->gpr[rd], regs->gpr[rb]);
-			goto logical_done;
+			goto logical_done_nocc;
 #endif
 		case 284:	/* xor */
 			op->val = ~(regs->gpr[rd] ^ regs->gpr[rb]);
@@ -1497,7 +1497,7 @@  int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 
 		case 378:	/* popcntw */
 			do_popcnt(regs, op, regs->gpr[rd], 32);
-			goto logical_done;
+			goto logical_done_nocc;
 
 		case 412:	/* orc */
 			op->val = regs->gpr[rd] | ~regs->gpr[rb];
@@ -1513,7 +1513,7 @@  int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 #ifdef CONFIG_PPC64
 		case 506:	/* popcntd */
 			do_popcnt(regs, op, regs->gpr[rd], 64);
-			goto logical_done;
+			goto logical_done_nocc;
 #endif
 		case 922:	/* extsh */
 			op->val = (signed short) regs->gpr[rd];