From 79c18be7dfe660ab48f9f535e6cabd38c9f1d73b Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 11 Mar 2011 08:12:24 +0000 Subject: target-arm: Correct ABD's handling of negative zeroes Implement ABD by taking the absolute value of the difference of the operands (as the ARM ARM specifies) rather than by flipping the order of the operands to the subtract based on the results of a comparison. The latter approch gives the wrong answers for some edge cases like negative zero. Signed-off-by: Peter Maydell Signed-off-by: Aurelien Jarno --- target-arm/neon_helper.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'target-arm') diff --git a/target-arm/neon_helper.c b/target-arm/neon_helper.c index 9d54a75ef3..bf324c62b6 100644 --- a/target-arm/neon_helper.c +++ b/target-arm/neon_helper.c @@ -1789,9 +1789,7 @@ uint32_t HELPER(neon_abd_f32)(uint32_t a, uint32_t b) { float32 f0 = make_float32(a); float32 f1 = make_float32(b); - return float32_val((float32_compare_quiet(f0, f1, NFS) == 1) - ? float32_sub(f0, f1, NFS) - : float32_sub(f1, f0, NFS)); + return float32_val(float32_abs(float32_sub(f0, f1, NFS))); } uint32_t HELPER(neon_add_f32)(uint32_t a, uint32_t b) -- cgit v1.2.3