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-rw-r--r--llvm/lib/Target/X86/X86InstrCompiler.td2
1 files changed, 2 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86InstrCompiler.td b/llvm/lib/Target/X86/X86InstrCompiler.td
index e7de24bca41..227f69a9d84 100644
--- a/llvm/lib/Target/X86/X86InstrCompiler.td
+++ b/llvm/lib/Target/X86/X86InstrCompiler.td
@@ -1232,6 +1232,8 @@ def : Pat<(store (add (loadi64 addr:$dst), 0x00000000800000000), addr:$dst),
// with implicit zero-extension instead of a 64-bit and if the immediate has at
// least 32 bits of leading zeros. If in addition the last 32 bits can be
// represented with a sign extension of a 8 bit constant, use that.
+// This can also reduce instruction size by eliminating the need for the REX
+// prefix.
let AddedComplexity = 1 in // Give priority over i64immSExt8.
def : Pat<(and GR64:$src, i64immZExt32SExt8:$imm),
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