Hi, > Where exactly does the test go wrong?
The test which fails is this one: TEST_EQ (double, __DBL_MAX__, __DBL_MAX__, 1); From the test file included in the patch. > Can you show a trace of __eqdf2 with register values? Sure thing, running for ARC700, using original implementation and enabled guarded code for FPX handling: [0x000002a2] 0xc000 K Z ld_s r0,[sp,0x0] : lw [0x5000c0c0] => 0xffffffff : (w1) r0 <= 0xffffffff * [0x000002a4] 0xc101 K Z ld_s r1,[sp,0x4] : lw [0x5000c0c4] => 0x7fefffff : (w1) r1 <= 0x7fefffff * [0x000002a6] 0xc202 K Z ld_s r2,[sp,0x8] : lw [0x5000c0c8] => 0xffffffff : (w1) r2 <= 0xffffffff * [0x000002a8] 0xc303 K Z ld_s r3,[sp,0xc] : lw [0x5000c0cc] => 0x7fefffff : (w1) r3 <= 0x7fefffff * [0x000002aa] 0x0aea0000 K Z bl 0x2e8 : (w0) r31 <= 0x000002ae * [0x00000590] 0x091d00e1 K Z brne.d r1,r3,0x1c [0x00000594] 0x2153050c K Z bmsk r12,r1,0x14 : (w0) r12 <= 0x000fffff * [0x00000598] 0x200580be K Z or.f 0,r0,r2 * [0x0000059c] 0x24cf1562 K N bset.ne r12,r12,0x15 : (w0) r12 <= 0x002fffff * [0x000005a0] 0x2414904c K N add1.f r12,r12,r1 : (w0) r12 <= 0x000ffffd * [0x000005a4] 0x7fe0 K C j_s.d [blink] * [0x000005a6] 0x20cc8086 KD C cmp.cc r0,r2 For reference, the routine: .global __eqdf2 .balign 4 HIDDEN_FUNC(__eqdf2) /* Good performance as long as the difference in high word is well predictable (as seen from the branch predictor). */ __eqdf2: brne.d DBL0H,DBL1H,.Lhighdiff bmsk r12,DBL0H,20 #ifndef __HS__ /* The next two instructions are required to recognize the FPX NaN, which has a pattern like this: 0x7ff0_0000_8000_0000, as oposite to 0x7ff8_0000_0000_0000. */ or.f 0,DBL0L,DBL1L bset.ne r12,r12,21 #endif /* __HS__ */ add1.f r12,r12,DBL0H /* set c iff NaN; also, clear z if NaN. */ j_s.d [blink] cmp.cc DBL0L,DBL1L .balign 4 .Lhighdiff: or r12,DBL0H,DBL1H or.f 0,DBL0L,DBL1L j_s.d [blink] bmsk.eq.f r12,r12,30 ENDFUNC(__eqdf2) All those results were collected using nsimfree. Please let me know if you need more info, Claudiu