[llvm] r352283 - [X86][SSE] Generalized unsigned compares to support nonsplat constant vectors (PR39859)

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Sat Jan 26 08:40:03 2019
New Revision: 352283

URL: http://llvm.org/viewvc/llvm-project?rev=352283&view=rev
Log:
[X86][SSE] Generalized unsigned compares to support nonsplat constant vectors (PR39859)

Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
    llvm/trunk/test/CodeGen/X86/sat-add.ll
    llvm/trunk/test/CodeGen/X86/vec_setcc-2.ll

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=352283&r1=352282&r2=352283&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Sat Jan 26 08:40:03 2019
@@ -19604,17 +19604,20 @@ static SDValue LowerVSETCC(SDValue Op, c
       TLI.isOperationLegal(ISD::UMIN, VT)) {
     // If we have a constant operand, increment/decrement it and change the
     // condition to avoid an invert.
-    // TODO: This could be extended to handle a non-splat constant by checking
-    // that each element of the constant is not the max/null value.
-    APInt C;
-    if (Cond == ISD::SETUGT && isConstantSplat(Op1, C) && !C.isMaxValue()) {
+    if (Cond == ISD::SETUGT &&
+        ISD::matchUnaryPredicate(Op1, [](ConstantSDNode *C) {
+          return !C->getAPIntValue().isMaxValue();
+        })) {
       // X > C --> X >= (C+1) --> X == umax(X, C+1)
-      Op1 = DAG.getConstant(C + 1, dl, VT);
+      Op1 = DAG.getNode(ISD::ADD, dl, VT, Op1, DAG.getConstant(1, dl, VT));
       Cond = ISD::SETUGE;
     }
-    if (Cond == ISD::SETULT && isConstantSplat(Op1, C) && !C.isNullValue()) {
+    if (Cond == ISD::SETULT &&
+        ISD::matchUnaryPredicate(Op1, [](ConstantSDNode *C) {
+          return !C->getAPIntValue().isNullValue();
+        })) {
       // X < C --> X <= (C-1) --> X == umin(X, C-1)
-      Op1 = DAG.getConstant(C - 1, dl, VT);
+      Op1 = DAG.getNode(ISD::SUB, dl, VT, Op1, DAG.getConstant(1, dl, VT));
       Cond = ISD::SETULE;
     }
     bool Invert = false;

Modified: llvm/trunk/test/CodeGen/X86/sat-add.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/sat-add.ll?rev=352283&r1=352282&r2=352283&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/sat-add.ll (original)
+++ llvm/trunk/test/CodeGen/X86/sat-add.ll Sat Jan 26 08:40:03 2019
@@ -551,11 +551,9 @@ define <4 x i32> @unsigned_sat_constant_
 ; SSE41:       # %bb.0:
 ; SSE41-NEXT:    movdqa {{.*#+}} xmm1 = [43,44,45,46]
 ; SSE41-NEXT:    paddd %xmm0, %xmm1
-; SSE41-NEXT:    movdqa {{.*#+}} xmm2 = [4294967252,4294967251,4294967250,4294967249]
-; SSE41-NEXT:    pminud %xmm0, %xmm2
+; SSE41-NEXT:    movdqa {{.*#+}} xmm2 = [4294967253,4294967252,4294967251,4294967250]
+; SSE41-NEXT:    pmaxud %xmm0, %xmm2
 ; SSE41-NEXT:    pcmpeqd %xmm2, %xmm0
-; SSE41-NEXT:    pcmpeqd %xmm2, %xmm2
-; SSE41-NEXT:    pxor %xmm2, %xmm0
 ; SSE41-NEXT:    por %xmm1, %xmm0
 ; SSE41-NEXT:    retq
   %a = add <4 x i32> %x, <i32 43, i32 44, i32 45, i32 46>

Modified: llvm/trunk/test/CodeGen/X86/vec_setcc-2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/vec_setcc-2.ll?rev=352283&r1=352282&r2=352283&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/vec_setcc-2.ll (original)
+++ llvm/trunk/test/CodeGen/X86/vec_setcc-2.ll Sat Jan 26 08:40:03 2019
@@ -511,11 +511,9 @@ define <4 x i1> @ugt_v4i32_nonsplat(<4 x
 ;
 ; SSE41-LABEL: ugt_v4i32_nonsplat:
 ; SSE41:       ## %bb.0:
-; SSE41-NEXT:    movdqa {{.*#+}} xmm1 = [4294967253,4294967254,4294967255,4294967256]
-; SSE41-NEXT:    pminud %xmm0, %xmm1
+; SSE41-NEXT:    movdqa {{.*#+}} xmm1 = [4294967254,4294967255,4294967256,4294967257]
+; SSE41-NEXT:    pmaxud %xmm0, %xmm1
 ; SSE41-NEXT:    pcmpeqd %xmm1, %xmm0
-; SSE41-NEXT:    pcmpeqd %xmm1, %xmm1
-; SSE41-NEXT:    pxor %xmm1, %xmm0
 ; SSE41-NEXT:    retq
   %cmp = icmp ugt <4 x i32> %x, <i32 -43, i32 -42, i32 -41, i32 -40>
   ret <4 x i1> %cmp