From 40244be3729149ff440caf18e445ec17b0d0b511 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Thu, 23 Jun 2016 22:17:41 +0000 Subject: Fix i386/x86_64 scalbl with sNaN input (bug 20296). The x86_64 and i386 versions of scalbl return sNaN for some cases of sNaN input and are missing "invalid" exceptions for other cases. This results from overly complicated code that either returns a NaN input, or discards both inputs when one is NaN and loads a NaN from memory. This patch fixes this by simplifying the code to add the arguments when either one is NaN. Tested for x86_64 and x86. [BZ #20296] * sysdeps/i386/fpu/e_scalbl.S (__ieee754_scalbl): Add arguments when either argument is a NaN. * sysdeps/x86_64/fpu/e_scalbl.S (__ieee754_scalbl): Likewise. * math/libm-test.inc (scalb_test_data): Add sNaN tests. --- sysdeps/i386/fpu/e_scalbl.S | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) (limited to 'sysdeps/i386/fpu') diff --git a/sysdeps/i386/fpu/e_scalbl.S b/sysdeps/i386/fpu/e_scalbl.S index d10b22e..896f599 100644 --- a/sysdeps/i386/fpu/e_scalbl.S +++ b/sysdeps/i386/fpu/e_scalbl.S @@ -45,7 +45,7 @@ ENTRY(__ieee754_scalbl) fnstsw andl $0x4500, %eax cmpl $0x0100, %eax - je 3f + je 2f fld %st(1) frndint fcomp %st(2) @@ -76,18 +76,8 @@ ENTRY(__ieee754_scalbl) fldl MOX(zero_nan, %eax, 1) ret - /* The result is NaN, but we must not raise an exception. - So use a variable. */ -2: fstp %st - fstp %st -#ifdef PIC - LOAD_PIC_REG (cx) -#endif - fldl MO(nan) - ret - - /* The first parameter is a NaN. Return it. */ -3: fstp %st(1) + /* The result is NaN; raise an exception for sNaN arguments. */ +2: faddp ret /* Return NaN and raise the invalid exception. */ -- cgit v1.1