From 8e2f4e971fa048f55428ca49c3a55fa5dc03bd52 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 6 Jun 2012 14:45:45 -0700 Subject: [PATCH] alpha: Fix [BZ #13718] The routines expect to be able to bias the count by a small number. If the count is near -1ull, the count will overflow. Since we cannot use the whole 64-bit address space, bound the count to LONG_MAX. --- ChangeLog.alpha | 4 ++++ sysdeps/alpha/alphaev6/stxncpy.S | 19 +++++++++++++------ sysdeps/alpha/stxncpy.S | 23 +++++++++++++---------- 3 files changed, 30 insertions(+), 16 deletions(-) diff --git a/ChangeLog.alpha b/ChangeLog.alpha index 0598d7ee19..d291df970a 100644 --- a/ChangeLog.alpha +++ b/ChangeLog.alpha @@ -1,5 +1,9 @@ 2012-06-06 Richard Henderson + [BZ #13718] + * sysdeps/alpha/stxncmp.S: Bound count to LONG_MAX at startup. + * sysdeps/alpha/alphaev6/stxncmp.S: Likewise. + * sysdeps/alpha/fpu/e_sqrt.c: Include before redefining __ieee758_sqrt. diff --git a/sysdeps/alpha/alphaev6/stxncpy.S b/sysdeps/alpha/alphaev6/stxncpy.S index d134eb8c10..28495df004 100644 --- a/sysdeps/alpha/alphaev6/stxncpy.S +++ b/sysdeps/alpha/alphaev6/stxncpy.S @@ -143,18 +143,25 @@ $a_eoc: .align 4 __stxncpy: /* Are source and destination co-aligned? */ + lda t2, -1 # E : xor a0, a1, t1 # E : and a0, 7, t0 # E : find dest misalignment - and t1, 7, t1 # E : (stall) - addq a2, t0, a2 # E : bias count by dest misalignment (stall) + nop # E : - subq a2, 1, a2 # E : + srl t2, 1, t2 # U : + and t1, 7, t1 # E : + cmovlt a2, t2, a2 # E : bound count to LONG_MAX (stall) + nop # E : + + addq a2, t0, a2 # E : bias count by dest misalignment + subq a2, 1, a2 # E : (stall) and a2, 7, t2 # E : (stall) - srl a2, 3, a2 # U : a2 = loop counter = (count - 1)/8 (stall) - addq zero, 1, t10 # E : + lda t10, 1 # E : + srl a2, 3, a2 # U : a2 = loop counter = (count - 1)/8 sll t10, t2, t10 # U : t10 = bitmask of last count byte - bne t1, $unaligned # U : + nop # E : + bne t1, $unaligned # U : (stall) /* We are co-aligned; take care of a partial first word. */ ldq_u t1, 0(a1) # L : load first src word diff --git a/sysdeps/alpha/stxncpy.S b/sysdeps/alpha/stxncpy.S index f8b494af0c..d2cb9c3c93 100644 --- a/sysdeps/alpha/stxncpy.S +++ b/sysdeps/alpha/stxncpy.S @@ -123,16 +123,19 @@ $a_eoc: .align 3 __stxncpy: /* Are source and destination co-aligned? */ - xor a0, a1, t1 # e0 : - and a0, 7, t0 # .. e1 : find dest misalignment - and t1, 7, t1 # e0 : - addq a2, t0, a2 # .. e1 : bias count by dest misalignment - subq a2, 1, a2 # e0 : - and a2, 7, t2 # e1 : - srl a2, 3, a2 # e0 : a2 = loop counter = (count - 1)/8 - addq zero, 1, t10 # .. e1 : - sll t10, t2, t10 # e0 : t10 = bitmask of last count byte - bne t1, $unaligned # .. e1 : + lda t2, -1 + xor a0, a1, t1 + srl t2, 1, t2 + and a0, 7, t0 # find dest misalignment + cmovlt a2, t2, a2 # bound neg count to LONG_MAX + and t1, 7, t1 + addq a2, t0, a2 # bias count by dest misalignment + subq a2, 1, a2 + and a2, 7, t2 + srl a2, 3, a2 # a2 = loop counter = (count - 1)/8 + addq zero, 1, t10 + sll t10, t2, t10 # t10 = bitmask of last count byte + bne t1, $unaligned /* We are co-aligned; take care of a partial first word. */ -- 2.43.5