[InstCombine] Combine XOR and AES instructions on ARM/ARM64.

The ARM/ARM64 AESE and AESD instructions have a builtin XOR as the first step in
the instruction. Therefore, if the AES key is zero and the AES data was
previously XORed, it can be combined into a single instruction.

Differential Revision: https://reviews.llvm.org/D47239
Patch by Michael Brase!

llvm-svn: 333193
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 8b7c282..a5a0edc 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -2966,6 +2966,23 @@
 
     break;
   }
+  case Intrinsic::arm_neon_aesd:
+  case Intrinsic::arm_neon_aese:
+  case Intrinsic::aarch64_crypto_aesd:
+  case Intrinsic::aarch64_crypto_aese: {
+    Value *DataArg = II->getArgOperand(0);
+    Value *KeyArg  = II->getArgOperand(1);
+
+    // Try to use the builtin XOR in AESE and AESD to eliminate a prior XOR
+    Value *Data, *Key;
+    if (match(KeyArg, m_ZeroInt()) &&
+        match(DataArg, m_Xor(m_Value(Data), m_Value(Key)))) {
+      II->setArgOperand(0, Data);
+      II->setArgOperand(1, Key);
+      return II;
+    }
+    break;
+  }
   case Intrinsic::amdgcn_rcp: {
     Value *Src = II->getArgOperand(0);
 
diff --git a/llvm/test/Transforms/InstCombine/AArch64/aes-intrinsics.ll b/llvm/test/Transforms/InstCombine/AArch64/aes-intrinsics.ll
new file mode 100644
index 0000000..c383859
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/AArch64/aes-intrinsics.ll
@@ -0,0 +1,44 @@
+; RUN: opt -S -instcombine < %s | FileCheck %s
+; ARM64 AES intrinsic variants
+
+define <16 x i8> @combineXorAeseZeroARM64(<16 x i8> %data, <16 x i8> %key) {
+; CHECK-LABEL: @combineXorAeseZeroARM64(
+; CHECK-NEXT:    %data.aes = tail call <16 x i8> @llvm.aarch64.crypto.aese(<16 x i8> %data, <16 x i8> %key)
+; CHECK-NEXT:    ret <16 x i8> %data.aes
+  %data.xor = xor <16 x i8> %data, %key
+  %data.aes = tail call <16 x i8> @llvm.aarch64.crypto.aese(<16 x i8> %data.xor, <16 x i8> zeroinitializer)
+  ret <16 x i8> %data.aes
+}
+
+define <16 x i8> @combineXorAeseNonZeroARM64(<16 x i8> %data, <16 x i8> %key) {
+; CHECK-LABEL: @combineXorAeseNonZeroARM64(
+; CHECK-NEXT:    %data.xor = xor <16 x i8> %data, %key
+; CHECK-NEXT:    %data.aes = tail call <16 x i8> @llvm.aarch64.crypto.aese(<16 x i8> %data.xor, <16 x i8> <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>)
+; CHECK-NEXT:    ret <16 x i8> %data.aes
+  %data.xor = xor <16 x i8> %data, %key
+  %data.aes = tail call <16 x i8> @llvm.aarch64.crypto.aese(<16 x i8> %data.xor, <16 x i8> <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>)
+  ret <16 x i8> %data.aes
+}
+
+define <16 x i8> @combineXorAesdZeroARM64(<16 x i8> %data, <16 x i8> %key) {
+; CHECK-LABEL: @combineXorAesdZeroARM64(
+; CHECK-NEXT:    %data.aes = tail call <16 x i8> @llvm.aarch64.crypto.aesd(<16 x i8> %data, <16 x i8> %key)
+; CHECK-NEXT:    ret <16 x i8> %data.aes
+  %data.xor = xor <16 x i8> %data, %key
+  %data.aes = tail call <16 x i8> @llvm.aarch64.crypto.aesd(<16 x i8> %data.xor, <16 x i8> zeroinitializer)
+  ret <16 x i8> %data.aes
+}
+
+define <16 x i8> @combineXorAesdNonZeroARM64(<16 x i8> %data, <16 x i8> %key) {
+; CHECK-LABEL: @combineXorAesdNonZeroARM64(
+; CHECK-NEXT:    %data.xor = xor <16 x i8> %data, %key
+; CHECK-NEXT:    %data.aes = tail call <16 x i8> @llvm.aarch64.crypto.aesd(<16 x i8> %data.xor, <16 x i8> <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>)
+; CHECK-NEXT:    ret <16 x i8> %data.aes
+  %data.xor = xor <16 x i8> %data, %key
+  %data.aes = tail call <16 x i8> @llvm.aarch64.crypto.aesd(<16 x i8> %data.xor, <16 x i8> <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>)
+  ret <16 x i8> %data.aes
+}
+
+declare <16 x i8> @llvm.aarch64.crypto.aese(<16 x i8>, <16 x i8>) #0
+declare <16 x i8> @llvm.aarch64.crypto.aesd(<16 x i8>, <16 x i8>) #0
+
diff --git a/llvm/test/Transforms/InstCombine/ARM/aes-intrinsics.ll b/llvm/test/Transforms/InstCombine/ARM/aes-intrinsics.ll
new file mode 100644
index 0000000..56eee54
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/ARM/aes-intrinsics.ll
@@ -0,0 +1,43 @@
+; RUN: opt -S -instcombine < %s | FileCheck %s
+; ARM AES intrinsic variants
+
+define <16 x i8> @combineXorAeseZeroARM(<16 x i8> %data, <16 x i8> %key) {
+; CHECK-LABEL: @combineXorAeseZeroARM(
+; CHECK-NEXT:    %data.aes = tail call <16 x i8> @llvm.arm.neon.aese(<16 x i8> %data, <16 x i8> %key)
+; CHECK-NEXT:    ret <16 x i8> %data.aes
+  %data.xor = xor <16 x i8> %data, %key
+  %data.aes = tail call <16 x i8> @llvm.arm.neon.aese(<16 x i8> %data.xor, <16 x i8> zeroinitializer)
+  ret <16 x i8> %data.aes
+}
+
+define <16 x i8> @combineXorAeseNonZeroARM(<16 x i8> %data, <16 x i8> %key) {
+; CHECK-LABEL: @combineXorAeseNonZeroARM(
+; CHECK-NEXT:    %data.xor = xor <16 x i8> %data, %key
+; CHECK-NEXT:    %data.aes = tail call <16 x i8> @llvm.arm.neon.aese(<16 x i8> %data.xor, <16 x i8> <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>)
+; CHECK-NEXT:    ret <16 x i8> %data.aes
+  %data.xor = xor <16 x i8> %data, %key
+  %data.aes = tail call <16 x i8> @llvm.arm.neon.aese(<16 x i8> %data.xor, <16 x i8> <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>)
+  ret <16 x i8> %data.aes
+}
+
+define <16 x i8> @combineXorAesdZeroARM(<16 x i8> %data, <16 x i8> %key) {
+; CHECK-LABEL: @combineXorAesdZeroARM(
+; CHECK-NEXT:    %data.aes = tail call <16 x i8> @llvm.arm.neon.aesd(<16 x i8> %data, <16 x i8> %key)
+; CHECK-NEXT:    ret <16 x i8> %data.aes
+  %data.xor = xor <16 x i8> %data, %key
+  %data.aes = tail call <16 x i8> @llvm.arm.neon.aesd(<16 x i8> %data.xor, <16 x i8> zeroinitializer)
+  ret <16 x i8> %data.aes
+}
+
+define <16 x i8> @combineXorAesdNonZeroARM(<16 x i8> %data, <16 x i8> %key) {
+; CHECK-LABEL: @combineXorAesdNonZeroARM(
+; CHECK-NEXT:    %data.xor = xor <16 x i8> %data, %key
+; CHECK-NEXT:    %data.aes = tail call <16 x i8> @llvm.arm.neon.aesd(<16 x i8> %data.xor, <16 x i8> <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>)
+; CHECK-NEXT:    ret <16 x i8> %data.aes
+  %data.xor = xor <16 x i8> %data, %key
+  %data.aes = tail call <16 x i8> @llvm.arm.neon.aesd(<16 x i8> %data.xor, <16 x i8> <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>)
+  ret <16 x i8> %data.aes
+}
+
+declare <16 x i8> @llvm.arm.neon.aese(<16 x i8>, <16 x i8>) #0
+declare <16 x i8> @llvm.arm.neon.aesd(<16 x i8>, <16 x i8>) #0