svn commit: r344496 - stable/12/sys/powerpc/fpu

[Justin Hibbits]

Author: jhibbits
Date: Sun Feb 24 20:15:16 2019
New Revision: 344496
URL: https://svnweb.freebsd.org/changeset/base/344496

Log:
  MFC r343078:
  
  powerpc: Fix FPU fsqrt emulation special case results
  
  If fsqrts is emulated with +INF as its argument, the 0 return value causes a
  NULL pointer dereference, panicking the system.  Follow the PowerISA and
  return +INF with no FP exception.

Modified:
  stable/12/sys/powerpc/fpu/fpu_sqrt.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/sys/powerpc/fpu/fpu_sqrt.c
==============================================================================
--- stable/12/sys/powerpc/fpu/fpu_sqrt.c	Sun Feb 24 19:31:42 2019	(r344495)
+++ stable/12/sys/powerpc/fpu/fpu_sqrt.c	Sun Feb 24 20:15:16 2019	(r344496)
@@ -226,12 +226,12 @@ fpu_sqrt(struct fpemu *fe)
 		return (x);
 	}
 	if (x->fp_sign) {
+		fe->fe_cx |= FPSCR_VXSQRT;
 		return (fpu_newnan(fe));
 	}
 	if (ISINF(x)) {
-		fe->fe_cx |= FPSCR_VXSQRT;
-		DUMPFPN(FPE_REG, 0);
-		return (0);
+		DUMPFPN(FPE_REG, x);
+		return (x);
 	}
 
 	/*