[PATCH] D19455: InstCombine: Reduce trunc (shl x, K) width.

[Matt Arsenault via llvm-commits]

arsenm added inline comments.

================
Comment at: lib/Transforms/InstCombine/InstCombineCasts.cpp:579-580
@@ +578,4 @@
+
+    // Transform "trunc (shl X, cst)" -> "shl (trunc X), cst" so long as the dest
+    // type isn't non-native and cst < size / 2
+    if (match(Src, m_Shl(m_Value(A), m_ConstantInt(Cst)))) {
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majnemer wrote:
> You don't seem to check if the dest type is legal.
This is handled by the above ShouldChangeType


http://reviews.llvm.org/D19455