search for: sse2conversiontbl

...finds cost as 30 for this operation. 30 cost for this operation looks very high. Wondering why such a high cost kept for this, any pointers to understand this will be helpful. In few cases this restricts better vectorization opportunities. Other observations: Cost for TRUNCATE v16i32 to v16i8 in SSE2ConversionTbl as 7. Cost for TRUNCATE v8i32 to v8i8 is 2 in AVX2 and 4 in AVX mode. Thanks, Ashutosh -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20160411/7233218b/attachment.html>

...ong> Thanks Elena. Mostly I was interested in why such a high cost 30 kept for TRUNCATE v16i32 to v16i8 in SSE41. Looking at the code it appears like TRUNCATE v16i32 to v16i8 in SSE41 is very expensive vs SSE2. I feel this number should be same/close to the cost mentioned for same operation in SSE2ConversionTbl. Below patch from Cong Hou reduce cost for same operation in SSE2 mode. http://reviews.llvm.org/rL256194 Looks like as the part of same patch we should reduce cost for TRUNCATE v16i32 to v16i8 in SSE4.1 as well. Regards, Ashutosh From: Demikhovsky, Elena [mailto:elena.demikhovsky at intel.com]...