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.

diff --git a/ChangeLog b/ChangeLog
index e654c95043652c04d073e3f7c511fe721faa8831..3d6dad216759484c0fb41eb4e1eebed40f84c3e8 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2016-06-23  Joseph Myers  <joseph@codesourcery.com>
 
+       [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.
+
        * math/libm-test.inc (snan_value_ld): New macro.
        (isgreater_test_data): Add sNaN tests.
        (isgreaterequal_test_data): Likewise.

diff --git a/math/libm-test.inc b/math/libm-test.inc
index 3e4ef187c311ac00c1d1d8458e91a4b33e363c74..7334a4857788d854e125f987412ad44cfcf4ab0d 100644 (file)
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -11598,6 +11598,10 @@ static const struct test_ff_f_data scalb_test_data[] =
     TEST_ff_f (scalb, 0, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (scalb, 1, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (scalb, 1, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (scalb, 0, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, 0, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, 1, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, 1, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
 
     TEST_ff_f (scalb, 1, 0, 1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (scalb, -1, 0, -1, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
@@ -11634,28 +11638,60 @@ static const struct test_ff_f_data scalb_test_data[] =
 
     TEST_ff_f (scalb, qnan_value, 1, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (scalb, -qnan_value, 1, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (scalb, snan_value, 1, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, -snan_value, 1, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
     TEST_ff_f (scalb, 1, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (scalb, 1, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (scalb, 1, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, 1, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
     TEST_ff_f (scalb, qnan_value, 0.5, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (scalb, -qnan_value, 0.5, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (scalb, snan_value, 0.5, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, -snan_value, 0.5, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
     TEST_ff_f (scalb, 0.5, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (scalb, 0.5, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (scalb, 0.5, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, 0.5, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
     TEST_ff_f (scalb, qnan_value, 0, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (scalb, -qnan_value, 0, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (scalb, snan_value, 0, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, -snan_value, 0, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
     TEST_ff_f (scalb, 0, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (scalb, 0, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (scalb, 0, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, 0, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
     TEST_ff_f (scalb, qnan_value, plus_infty, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (scalb, -qnan_value, plus_infty, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (scalb, snan_value, plus_infty, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, -snan_value, plus_infty, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
     TEST_ff_f (scalb, plus_infty, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (scalb, plus_infty, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (scalb, plus_infty, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, plus_infty, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
     TEST_ff_f (scalb, qnan_value, minus_infty, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (scalb, -qnan_value, minus_infty, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (scalb, snan_value, minus_infty, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, -snan_value, minus_infty, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
     TEST_ff_f (scalb, minus_infty, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (scalb, minus_infty, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (scalb, minus_infty, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, minus_infty, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
     TEST_ff_f (scalb, qnan_value, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (scalb, qnan_value, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (scalb, -qnan_value, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_ff_f (scalb, -qnan_value, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (scalb, snan_value, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, snan_value, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, -snan_value, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, -snan_value, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, qnan_value, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, qnan_value, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, -qnan_value, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, -qnan_value, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, snan_value, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, snan_value, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, -snan_value, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (scalb, -snan_value, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
 
     TEST_ff_f (scalb, max_value, max_value, plus_oflow, INEXACT_EXCEPTION|OVERFLOW_EXCEPTION|ERRNO_PLUS_OFLOW),
     TEST_ff_f (scalb, max_value, -max_value, plus_uflow, INEXACT_EXCEPTION|UNDERFLOW_EXCEPTION|ERRNO_PLUS_UFLOW),

diff --git a/sysdeps/i386/fpu/e_scalbl.S b/sysdeps/i386/fpu/e_scalbl.S
index d10b22ea834424efe1ffc046810ff8606837703e..896f599cb061e2cb513b7fd729a2e9cc1000f88a 100644 (file)
--- 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.  */

diff --git a/sysdeps/x86_64/fpu/e_scalbl.S b/sysdeps/x86_64/fpu/e_scalbl.S
index 331bee580c49b641ba7b7d3ff1467d1a4dd959a7..2982dc3b9e7cb0d9b2bffaf6744eed42b8213738 100644 (file)
--- a/sysdeps/x86_64/fpu/e_scalbl.S
+++ b/sysdeps/x86_64/fpu/e_scalbl.S
@@ -44,7 +44,7 @@ ENTRY(__ieee754_scalbl)
        fnstsw
        andl    $0x4500, %eax
        cmpl    $0x0100, %eax
-       je      3f
+       je      2f
        fld     %st(1)
        frndint
        fcomip  %st(2), %st
@@ -75,15 +75,8 @@ ENTRY(__ieee754_scalbl)
 #endif
        ret
 
-       /* The result is NaN, but we must not raise an exception.
-          So use a variable.  */
-2:     fstp    %st
-       fstp    %st
-       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.  */