From c6749c42c35e09b1b810f4c645551f0d69a22717 Mon Sep 17 00:00:00 2001
From: Reid Spencer
In reverse mode, a similar computation is made except that the bits replaced -wrap around to include both the highest and lowest bits. For example, if a -16 bit value is being replaced then %lo=8 and %hi=4 would -cause these bits to be set: 0xFF1F.
+In reverse mode, a similar computation is made except that the bits are +reversed. That is, the 0th bit in %repl replaces the +%hi bit in %val and etc. down to the %loth bit.
llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F - llvm.part.set(0xFFFF, 0, 7, 4) -> 0x0060 - llvm.part.set(0xFFFF, 0, 8, 3) -> 0x00F0 + llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F + llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F + llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7 llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07