Simon Tatham 4dbfeb87c3 [ARM][MVE] Add intrinsics for immediate shifts. (reland) ... This adds the family of `vshlq_n` and `vshrq_n` ACLE intrinsics, which shift every lane of a vector left or right by a compile-time immediate. They mostly work by expanding to the IR `shl`, `lshr` and `ashr` operations, with their second operand being a vector splat of the immediate. There's a fiddly special case, though. ACLE specifies that the immediate in `vshrq_n` can take values up to //and including// the bit size of the vector lane. But LLVM IR thinks that shifting right by the full size of the lane is UB, and feels free to replace the `lshr` with an `undef` half way through the optimization pipeline. Hence, to keep this legal in source code, I have to detect it at codegen time. Logical (unsigned) right shifts by the element size are handled by simply emitting the zero vector; arithmetic ones are converted into a shift of one bit less, which will always give the same output. In order to do that check, I also had to enhance the tablegen MveEmitter so that it can cope with converting a builtin function's operand into a bare integer to pass to a code-generating subfunction. Previously the only bare integers it knew how to handle were flags generated from within `arm_mve.td`. Reviewers: dmgreen, miyuki, MarkMurrayARM, ostannard Reviewed By: dmgreen, MarkMurrayARM Subscribers: echristo, hokein, rdhindsa, kristof.beyls, hiraditya, cfe-commits, llvm-commits Tags: #clang, #llvm Differential Revision: https://reviews.llvm.org/D71065		2019-12-11 10:10:09 +00:00
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llvm	[ARM][MVE] Add intrinsics for immediate shifts. (reland)	2019-12-11 10:10:09 +00:00
llvm-c	Recommit "[DWARF5]Addition of alignment atrribute in typedef DIE."	2019-12-03 09:51:43 +05:30