powerpc/math_emu/efp: No need to round if the result is exact
Signed-off-by: Liu Yu <yu.liu@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/math-emu/math_efp.c b/arch/powerpc/math-emu/math_efp.c
index 10fda0f..96dbbae 100644
--- a/arch/powerpc/math-emu/math_efp.c
+++ b/arch/powerpc/math-emu/math_efp.c
@@ -676,13 +676,20 @@
type = insn_type(speinsn & 0x7ff);
if (type == XCR) return -ENOSYS;
+ __FPU_FPSCR = mfspr(SPRN_SPEFSCR);
+ pr_debug("speinsn:%08lx spefscr:%08lx\n", speinsn, __FPU_FPSCR);
+
+ /* No need to round if the result is exact */
+ if (!(__FPU_FPSCR & FP_EX_INEXACT))
+ return 0;
+
fc = (speinsn >> 21) & 0x1f;
s_lo = regs->gpr[fc] & SIGN_BIT_S;
s_hi = current->thread.evr[fc] & SIGN_BIT_S;
fgpr.wp[0] = current->thread.evr[fc];
fgpr.wp[1] = regs->gpr[fc];
- __FPU_FPSCR = mfspr(SPRN_SPEFSCR);
+ pr_debug("round fgpr: %08x %08x\n", fgpr.wp[0], fgpr.wp[1]);
switch ((speinsn >> 5) & 0x7) {
/* Since SPE instructions on E500 core can handle round to nearest
@@ -722,6 +729,8 @@
current->thread.evr[fc] = fgpr.wp[0];
regs->gpr[fc] = fgpr.wp[1];
+ pr_debug(" to fgpr: %08x %08x\n", fgpr.wp[0], fgpr.wp[1]);
+
return 0;
}