[PATCH] D19675: [InstCombine][AVX2] Add support for simplifying AVX2 per-element shifts to native shifts

[David Majnemer via llvm-commits]

majnemer added a subscriber: majnemer.

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Comment at: lib/Transforms/InstCombine/InstCombineCalls.cpp:339-354
@@ +338,18 @@
+    return nullptr;
+  case Intrinsic::x86_avx2_psrav_d:
+  case Intrinsic::x86_avx2_psrav_d_256:
+    LogicalShift = false;
+    ShiftLeft = false;
+    break;
+  case Intrinsic::x86_avx2_psrlv_d:
+  case Intrinsic::x86_avx2_psrlv_d_256:
+  case Intrinsic::x86_avx2_psrlv_q:
+  case Intrinsic::x86_avx2_psrlv_q_256:
+    LogicalShift = true;
+    ShiftLeft = false;
+    break;
+  case Intrinsic::x86_avx2_psllv_d:
+  case Intrinsic::x86_avx2_psllv_d_256:
+  case Intrinsic::x86_avx2_psllv_q:
+  case Intrinsic::x86_avx2_psllv_q_256:
+    LogicalShift = true;
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Er, why do we even have these intrinsics?
They seem sorta pointless, it seems way better to get rid of these and replace their use in clang's headers with a generic shift which sanitizes the shift amount.


Repository:
  rL LLVM

http://reviews.llvm.org/D19675