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6f0f237bf5
i386 exp, hypot and pow functions can return overflowing and underflowing values with excess range and precision; ; Wilco Dijkstra's patches to make isfinite etc. expand inline cause this pre-existing issue to result in test failures. This patch fixes those functions to avoid excess range and precision in their return values. Appropriate macros are added for the repeated code sequences; in future I'll add more such macros and refactor existing code forcing underflow (with or without also eliminating excess range and precision from the return value) to use such macros. Tested for x86. If, after this patch, you still see x86 libm test failures with excess range or precision, please file bugs in Bugzilla. [BZ #18980] * sysdeps/i386/fpu/i386-math-asm.h (DEFINE_FLT_MIN): New macro. (DEFINE_DBL_MIN): Likewise. (FLT_NARROW_EVAL_UFLOW_NONNEG_NAN): Likewise. (DBL_NARROW_EVAL_UFLOW_NONNEG_NAN): Likewise. (FLT_NARROW_EVAL_UFLOW_NONNEG): Likewise. (DBL_NARROW_EVAL_UFLOW_NONNEG): Likewise. * sysdeps/i386/fpu/e_exp.S: Include <i386-math-asm.h>. (dbl_min): Replace with use of DEFINE_DBL_MIN. (__ieee754_exp): Use DBL_NARROW_EVAL_UFLOW_NONNEG_NAN. (__exp_finite): Use DBL_NARROW_EVAL_UFLOW_NONNEG. * sysdeps/i386/fpu/e_exp10.S: Include <i386-math-asm.h>. (dbl_min): Replace with use of DEFINE_DBL_MIN. (__ieee754_exp10): Use DBL_NARROW_EVAL_UFLOW_NONNEG_NAN. * sysdeps/i386/fpu/e_exp10f.S: Include <i386-math-asm.h>. (flt_min): Replace with use of DEFINE_FLT_MIN. (__ieee754_exp10f): Use FLT_NARROW_EVAL_UFLOW_NONNEG_NAN. * sysdeps/i386/fpu/e_exp2.S: Include <i386-math-asm.h>. (dbl_min): Replace with use of DEFINE_DBL_MIN. (__ieee754_exp2): Use DBL_NARROW_EVAL_UFLOW_NONNEG_NAN. * sysdeps/i386/fpu/e_exp2f.S: Include <i386-math-asm.h>. (flt_min): Replace with use of DEFINE_FLT_MIN. (__ieee754_exp2f): Use FLT_NARROW_EVAL_UFLOW_NONNEG_NAN. * sysdeps/i386/fpu/e_expf.S: Include <i386-math-asm.h>. (flt_min): Replace with use of DEFINE_FLT_MIN. (__ieee754_expf): Use FLT_NARROW_EVAL_UFLOW_NONNEG_NAN. (__expf_finite): Use FLT_NARROW_EVAL_UFLOW_NONNEG. * sysdeps/i386/fpu/e_hypot.S: Include <i386-math-asm.h>. (__ieee754_hypot): Use DBL_NARROW_EVAL. * sysdeps/i386/fpu/e_hypotf.S: Include <i386-math-asm.h>. (__ieee754_hypotf): Use FLT_NARROW_EVAL. * sysdeps/i386/fpu/e_pow.S: Include <i386-math-asm.h>. (__ieee754_pow): Use DBL_NARROW_EVAL. * sysdeps/i386/fpu/e_powf.S: Include <i386-math-asm.h>. (__ieee754_powf): Use FLT_NARROW_EVAL. * sysdeps/i386/i686/fpu/multiarch/e_expf-sse2.S (__ieee754_expf_sse2): Convert double-precision result to single precision. * sysdeps/i386/fpu/libm-test-ulps: Update.
54 lines
1.1 KiB
ArmAsm
54 lines
1.1 KiB
ArmAsm
/*
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* Written by Ulrich Drepper <drepper@cygnus.com>.
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*/
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#include <machine/asm.h>
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#include <i386-math-asm.h>
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DEFINE_DBL_MIN
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#ifdef PIC
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# define MO(op) op##@GOTOFF(%ecx)
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#else
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# define MO(op) op
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#endif
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.text
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/* 10^x = 2^(x * log2(10)) */
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ENTRY(__ieee754_exp10)
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#ifdef PIC
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LOAD_PIC_REG (cx)
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#endif
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fldl 4(%esp)
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/* I added the following ugly construct because exp(+-Inf) resulted
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in NaN. The ugliness results from the bright minds at Intel.
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For the i686 the code can be written better.
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-- drepper@cygnus.com. */
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fxam /* Is NaN or +-Inf? */
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fstsw %ax
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movb $0x45, %dh
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andb %ah, %dh
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cmpb $0x05, %dh
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je 1f /* Is +-Inf, jump. */
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fldl2t
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fmulp /* x * log2(10) */
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fld %st
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frndint /* int(x * log2(10)) */
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fsubr %st,%st(1) /* fract(x * log2(10)) */
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fxch
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f2xm1 /* 2^(fract(x * log2(10))) - 1 */
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fld1
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faddp /* 2^(fract(x * log2(10))) */
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fscale /* e^x */
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fstp %st(1)
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DBL_NARROW_EVAL_UFLOW_NONNEG_NAN
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ret
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1: testl $0x200, %eax /* Test sign. */
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jz 2f /* If positive, jump. */
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fstp %st
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fldz /* Set result to 0. */
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2: ret
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END (__ieee754_exp10)
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strong_alias (__ieee754_exp10, __exp10_finite)
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