[PATCH v2 1/2] powerpc/math-emu: remove the dead code in math.c
Kevin Hao
haokexin at gmail.com
Wed Jul 10 21:34:56 EST 2013
The math.c is only built when CONFIG_MATH_EMULATION is enabled.
So we would never get into the case that CONFIG_MATH_EMULATION
is not defined in this file.
It seems that these codes have been there for a very long time.
Benjamin Herrenschmidt has gave a detailed background of them.
This is ancient code that was meant to emulate only load/stores/fmr
without the rest of the emulation. The goal was to be able to boot
userspace that was compiled without -msoft-float to *some* extent
(bcs it would potentially use fp load/stores for things like memcpy)
on small CPUs where the kernel footprint was critical.
It's been obsolete for a while now.
Signed-off-by: Kevin Hao <haokexin at gmail.com>
---
v2: Update the commit log as requested by Michael.
arch/powerpc/math-emu/math.c | 42 ------------------------------------------
1 file changed, 42 deletions(-)
diff --git a/arch/powerpc/math-emu/math.c b/arch/powerpc/math-emu/math.c
index 0328e66..cefb4f2 100644
--- a/arch/powerpc/math-emu/math.c
+++ b/arch/powerpc/math-emu/math.c
@@ -231,47 +231,6 @@ do_mathemu(struct pt_regs *regs)
if (get_user(insn, (u32 *)pc))
return -EFAULT;
-#ifndef CONFIG_MATH_EMULATION
- switch (insn >> 26) {
- case LFD:
- idx = (insn >> 16) & 0x1f;
- sdisp = (insn & 0xffff);
- op0 = (void *)¤t->thread.TS_FPR((insn >> 21) & 0x1f);
- op1 = (void *)((idx ? regs->gpr[idx] : 0) + sdisp);
- lfd(op0, op1, op2, op3);
- break;
- case LFDU:
- idx = (insn >> 16) & 0x1f;
- sdisp = (insn & 0xffff);
- op0 = (void *)¤t->thread.TS_FPR((insn >> 21) & 0x1f);
- op1 = (void *)((idx ? regs->gpr[idx] : 0) + sdisp);
- lfd(op0, op1, op2, op3);
- regs->gpr[idx] = (unsigned long)op1;
- break;
- case STFD:
- idx = (insn >> 16) & 0x1f;
- sdisp = (insn & 0xffff);
- op0 = (void *)¤t->thread.TS_FPR((insn >> 21) & 0x1f);
- op1 = (void *)((idx ? regs->gpr[idx] : 0) + sdisp);
- stfd(op0, op1, op2, op3);
- break;
- case STFDU:
- idx = (insn >> 16) & 0x1f;
- sdisp = (insn & 0xffff);
- op0 = (void *)¤t->thread.TS_FPR((insn >> 21) & 0x1f);
- op1 = (void *)((idx ? regs->gpr[idx] : 0) + sdisp);
- stfd(op0, op1, op2, op3);
- regs->gpr[idx] = (unsigned long)op1;
- break;
- case OP63:
- op0 = (void *)¤t->thread.TS_FPR((insn >> 21) & 0x1f);
- op1 = (void *)¤t->thread.TS_FPR((insn >> 11) & 0x1f);
- fmr(op0, op1, op2, op3);
- break;
- default:
- goto illegal;
- }
-#else /* CONFIG_MATH_EMULATION */
switch (insn >> 26) {
case LFS: func = lfs; type = D; break;
case LFSU: func = lfs; type = DU; break;
@@ -485,7 +444,6 @@ do_mathemu(struct pt_regs *regs)
default:
break;
}
-#endif /* CONFIG_MATH_EMULATION */
regs->nip += 4;
return 0;
--
1.8.1.4
More information about the Linuxppc-dev
mailing list