From 611f9f92fcb1a0bdcfd481dbf7ee67be04dd54e0 Mon Sep 17 00:00:00 2001
From: Sanjay Patel <spatel@rotateright.com>
Date: Thu, 27 Oct 2016 17:30:50 +0000
Subject: [PATCH] [InstCombine] handle simple vector integer constants in
 IsFreeToInvert

llvm-svn: 285318
---
 .../Transforms/InstCombine/InstCombineInternal.h   | 18 ++++++++++++
 llvm/test/Transforms/InstCombine/max-of-nots.ll    | 32 ++++++++++++++++------
 2 files changed, 42 insertions(+), 8 deletions(-)

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
index e85b3a5..176b7a0 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
+++ b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
@@ -84,6 +84,24 @@ static inline bool IsFreeToInvert(Value *V, bool WillInvertAllUses) {
   if (isa<ConstantInt>(V))
     return true;
 
+  // A vector of constant integers can be inverted easily.
+  Constant *CV;
+  if (V->getType()->isVectorTy() && match(V, PatternMatch::m_Constant(CV))) {
+    unsigned NumElts = V->getType()->getVectorNumElements();
+    for (unsigned i = 0; i != NumElts; ++i) {
+      Constant *Elt = CV->getAggregateElement(i);
+      if (!Elt)
+        return false;
+
+      if (isa<UndefValue>(Elt))
+        continue;
+
+      if (!isa<ConstantInt>(Elt))
+        return false;
+    }
+    return true;
+  }
+
   // Compares can be inverted if all of their uses are being modified to use the
   // ~V.
   if (isa<CmpInst>(V))
diff --git a/llvm/test/Transforms/InstCombine/max-of-nots.ll b/llvm/test/Transforms/InstCombine/max-of-nots.ll
index a329168..d9a13e5 100644
--- a/llvm/test/Transforms/InstCombine/max-of-nots.ll
+++ b/llvm/test/Transforms/InstCombine/max-of-nots.ll
@@ -88,16 +88,14 @@ define i32 @max_of_nots(i32 %x, i32 %y) {
   ret i32 %smax96
 }
 
-; FIXME - vectors should get the same folds
 define <2 x i32> @max_of_nots_vec(<2 x i32> %x, <2 x i32> %y) {
 ; CHECK-LABEL: @max_of_nots_vec(
-; CHECK-NEXT:    [[C0:%.*]] = icmp sgt <2 x i32> %y, zeroinitializer
-; CHECK-NEXT:    [[XOR_Y:%.*]] = xor <2 x i32> %y, <i32 -1, i32 -1>
-; CHECK-NEXT:    [[S0:%.*]] = select <2 x i1> [[C0]], <2 x i32> [[XOR_Y]], <2 x i32> <i32 -1, i32 -1>
-; CHECK-NEXT:    [[XOR_X:%.*]] = xor <2 x i32> %x, <i32 -1, i32 -1>
-; CHECK-NEXT:    [[C1:%.*]] = icmp slt <2 x i32> [[S0]], [[XOR_X]]
-; CHECK-NEXT:    [[SMAX96:%.*]] = select <2 x i1> [[C1]], <2 x i32> [[XOR_X]], <2 x i32> [[S0]]
-; CHECK-NEXT:    ret <2 x i32> [[SMAX96]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt <2 x i32> %y, zeroinitializer
+; CHECK-NEXT:    [[TMP2:%.*]] = select <2 x i1> [[TMP1]], <2 x i32> %y, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[TMP3:%.*]] = icmp slt <2 x i32> [[TMP2]], %x
+; CHECK-NEXT:    [[TMP4:%.*]] = select <2 x i1> [[TMP3]], <2 x i32> [[TMP2]], <2 x i32> %x
+; CHECK-NEXT:    [[TMP5:%.*]] = xor <2 x i32> [[TMP4]], <i32 -1, i32 -1>
+; CHECK-NEXT:    ret <2 x i32> [[TMP5]]
 ;
   %c0 = icmp sgt <2 x i32> %y, zeroinitializer
   %xor_y = xor <2 x i32> %y, <i32 -1, i32 -1>
@@ -108,3 +106,21 @@ define <2 x i32> @max_of_nots_vec(<2 x i32> %x, <2 x i32> %y) {
   ret <2 x i32> %smax96
 }
 
+define <2 x i37> @max_of_nots_weird_type_vec(<2 x i37> %x, <2 x i37> %y) {
+; CHECK-LABEL: @max_of_nots_weird_type_vec(
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt <2 x i37> %y, zeroinitializer
+; CHECK-NEXT:    [[TMP2:%.*]] = select <2 x i1> [[TMP1]], <2 x i37> %y, <2 x i37> zeroinitializer
+; CHECK-NEXT:    [[TMP3:%.*]] = icmp slt <2 x i37> [[TMP2]], %x
+; CHECK-NEXT:    [[TMP4:%.*]] = select <2 x i1> [[TMP3]], <2 x i37> [[TMP2]], <2 x i37> %x
+; CHECK-NEXT:    [[TMP5:%.*]] = xor <2 x i37> [[TMP4]], <i37 -1, i37 -1>
+; CHECK-NEXT:    ret <2 x i37> [[TMP5]]
+;
+  %c0 = icmp sgt <2 x i37> %y, zeroinitializer
+  %xor_y = xor <2 x i37> %y, <i37 -1, i37 -1>
+  %s0 = select <2 x i1> %c0, <2 x i37> %xor_y, <2 x i37> <i37 -1, i37 -1>
+  %xor_x = xor <2 x i37> %x, <i37 -1, i37 -1>
+  %c1 = icmp slt <2 x i37> %s0, %xor_x
+  %smax96 = select <2 x i1> %c1, <2 x i37> %xor_x, <2 x i37> %s0
+  ret <2 x i37> %smax96
+}
+
-- 
2.7.4