fix regression in x86_64 math asm with old binutils

the implicit-operand form of fucomip is rejected by binutils 2.19 and
perhaps other versions still in use. writing both operands explicitly
fixes the issue. there is no change to the resulting output.

commit a732e80d33b4fd6f510f7cec4f5573ef5d89bc4e was the source of this
regression.

diff --git a/src/math/x32/exp2l.s b/src/math/x32/exp2l.s
index dfb2bc7cca376ad62660ce23a5713b5d4b318e1d..e9edb96f23b17820da18216f5aee9e31fb644d30 100644 (file)
--- a/src/math/x32/exp2l.s
+++ b/src/math/x32/exp2l.s
@@ -6,7 +6,7 @@ expm1l:
        fmulp
        movl $0xc2820000,-4(%esp)
        flds -4(%esp)
-       fucomip %st(1)
+       fucomip %st(1),%st
        fld1
        jb 1f
                # x*log2e <= -65, return -1 without underflow
@@ -15,7 +15,7 @@ expm1l:
        ret
 1:     fld %st(1)
        fabs
-       fucomip %st(1)
+       fucomip %st(1),%st
        fstp %st(0)
        ja 1f
        f2xm1
@@ -48,7 +48,7 @@ exp2l:
        fld %st(1)
        fsub %st(1)
        faddp
-       fucomip %st(1)
+       fucomip %st(1),%st
        je 2f             # x - 0x1p63 + 0x1p63 == x
        movl $1,(%esp)
        flds (%esp)       # 0x1p-149

diff --git a/src/math/x86_64/exp2l.s b/src/math/x86_64/exp2l.s
index 0e9bdf9f39517f564225199d66d286ad855d4ba7..effab2bd4eb2d355ed11c436500a3f97544fa11f 100644 (file)
--- a/src/math/x86_64/exp2l.s
+++ b/src/math/x86_64/exp2l.s
@@ -6,7 +6,7 @@ expm1l:
        fmulp
        movl $0xc2820000,-4(%rsp)
        flds -4(%rsp)
-       fucomip %st(1)
+       fucomip %st(1),%st
        fld1
        jb 1f
                # x*log2e <= -65, return -1 without underflow
@@ -15,7 +15,7 @@ expm1l:
        ret
 1:     fld %st(1)
        fabs
-       fucomip %st(1)
+       fucomip %st(1),%st
        fstp %st(0)
        ja 1f
        f2xm1
@@ -48,7 +48,7 @@ exp2l:
        fld %st(1)
        fsub %st(1)
        faddp
-       fucomip %st(1)
+       fucomip %st(1),%st
        je 2f             # x - 0x1p63 + 0x1p63 == x
        movl $1,(%rsp)
        flds (%rsp)       # 0x1p-149