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[Qemu-devel] [PATCH v3 2/4] softfloat: Specialize udiv_qrnnd for x86_64
From: |
Richard Henderson |
Subject: |
[Qemu-devel] [PATCH v3 2/4] softfloat: Specialize udiv_qrnnd for x86_64 |
Date: |
Thu, 4 Oct 2018 12:56:58 -0500 |
The ISA has a 128/64-bit division instruction.
Tested-by: Emilio G. Cota <address@hidden>
Tested-by: Alex Bennée <address@hidden>
Reviewed-by: Alex Bennée <address@hidden>
Signed-off-by: Richard Henderson <address@hidden>
---
include/fpu/softfloat-macros.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/include/fpu/softfloat-macros.h b/include/fpu/softfloat-macros.h
index a1d99c730d..39eb08b4f1 100644
--- a/include/fpu/softfloat-macros.h
+++ b/include/fpu/softfloat-macros.h
@@ -637,6 +637,11 @@ static inline uint64_t estimateDiv128To64(uint64_t a0,
uint64_t a1, uint64_t b)
static inline uint64_t udiv_qrnnd(uint64_t *r, uint64_t n1,
uint64_t n0, uint64_t d)
{
+#if defined(__x86_64__)
+ uint64_t q;
+ asm("divq %4" : "=a"(q), "=d"(*r) : "0"(n0), "1"(n1), "rm"(d));
+ return q;
+#else
uint64_t d0, d1, q0, q1, r1, r0, m;
d0 = (uint32_t)d;
@@ -676,6 +681,7 @@ static inline uint64_t udiv_qrnnd(uint64_t *r, uint64_t n1,
*r = r0;
return (q1 << 32) | q0;
+#endif
}
/*----------------------------------------------------------------------------
--
2.17.1