[llvm] r288499 - [X86][SSE] Add support for extracting constant bit data from broadcasted constants

Simon Pilgrim via llvm-commits llvm-commits at lists.llvm.org
Fri Dec 2 05:16:08 PST 2016


Author: rksimon
Date: Fri Dec  2 07:16:08 2016
New Revision: 288499

URL: http://llvm.org/viewvc/llvm-project?rev=288499&view=rev
Log:
[X86][SSE] Add support for extracting constant bit data from broadcasted constants

Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
    llvm/trunk/test/CodeGen/X86/clear_upper_vector_element_bits.ll
    llvm/trunk/test/CodeGen/X86/vec_int_to_fp.ll
    llvm/trunk/test/CodeGen/X86/vec_uint_to_fp-fastmath.ll

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=288499&r1=288498&r2=288499&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Fri Dec  2 07:16:08 2016
@@ -5138,6 +5138,8 @@ static bool getTargetConstantBitsFromNod
   assert(UndefElts.empty() && "Expected an empty UndefElts vector");
   assert(EltBits.empty() && "Expected an empty EltBits vector");
 
+  Op = peekThroughBitcasts(Op);
+
   EVT VT = Op.getValueType();
   unsigned SizeInBits = VT.getSizeInBits();
   assert((SizeInBits % EltSizeInBits) == 0 && "Can't split constant!");
@@ -5170,35 +5172,35 @@ static bool getTargetConstantBitsFromNod
     return true;
   };
 
-  // Extract constant bits from constant pool scalar/vector.
+  auto ExtractConstantBits = [SizeInBits](const Constant *Cst, APInt &Mask,
+                                          APInt &Undefs) {
+    if (!Cst)
+      return false;
+    unsigned CstSizeInBits = Cst->getType()->getPrimitiveSizeInBits();
+    if (isa<UndefValue>(Cst)) {
+      Mask = APInt::getNullValue(SizeInBits);
+      Undefs = APInt::getLowBitsSet(SizeInBits, CstSizeInBits);
+      return true;
+    }
+    if (auto *CInt = dyn_cast<ConstantInt>(Cst)) {
+      Mask = CInt->getValue().zextOrTrunc(SizeInBits);
+      Undefs = APInt::getNullValue(SizeInBits);
+      return true;
+    }
+    if (auto *CFP = dyn_cast<ConstantFP>(Cst)) {
+      Mask = CFP->getValueAPF().bitcastToAPInt().zextOrTrunc(SizeInBits);
+      Undefs = APInt::getNullValue(SizeInBits);
+      return true;
+    }
+    return false;
+  };
+
+  // Extract constant bits from constant pool vector.
   if (auto *Cst = getTargetConstantFromNode(Op)) {
     Type *CstTy = Cst->getType();
     if (!CstTy->isVectorTy() || (SizeInBits != CstTy->getPrimitiveSizeInBits()))
       return false;
 
-    auto ExtractConstantBits = [SizeInBits](const Constant *Cst, APInt &Mask,
-                                            APInt &Undefs) {
-      if (!Cst)
-        return false;
-      unsigned CstSizeInBits = Cst->getType()->getPrimitiveSizeInBits();
-      if (isa<UndefValue>(Cst)) {
-        Mask = APInt::getNullValue(SizeInBits);
-        Undefs = APInt::getLowBitsSet(SizeInBits, CstSizeInBits);
-        return true;
-      }
-      if (auto *CInt = dyn_cast<ConstantInt>(Cst)) {
-        Mask = CInt->getValue().zextOrTrunc(SizeInBits);
-        Undefs = APInt::getNullValue(SizeInBits);
-        return true;
-      }
-      if (auto *CFP = dyn_cast<ConstantFP>(Cst)) {
-        Mask = CFP->getValueAPF().bitcastToAPInt().zextOrTrunc(SizeInBits);
-        Undefs = APInt::getNullValue(SizeInBits);
-        return true;
-      }
-      return false;
-    };
-
     unsigned CstEltSizeInBits = CstTy->getScalarSizeInBits();
     for (unsigned i = 0, e = CstTy->getVectorNumElements(); i != e; ++i) {
       APInt Bits, Undefs;
@@ -5211,9 +5213,27 @@ static bool getTargetConstantBitsFromNod
     return SplitBitData();
   }
 
+  // Extract constant bits from a broadcasted constant pool scalar.
+  if (Op.getOpcode() == X86ISD::VBROADCAST &&
+      EltSizeInBits <= Op.getScalarValueSizeInBits()) {
+    if (auto *Broadcast = getTargetConstantFromNode(Op.getOperand(0))) {
+      APInt Bits, Undefs;
+      if (ExtractConstantBits(Broadcast, Bits, Undefs)) {
+        unsigned NumBroadcastBits = Op.getScalarValueSizeInBits();
+        unsigned NumBroadcastElts = SizeInBits / NumBroadcastBits;
+        for (unsigned i = 0; i != NumBroadcastElts; ++i) {
+          MaskBits |= Bits.shl(i * NumBroadcastBits);
+          UndefBits |= Undefs.shl(i * NumBroadcastBits);
+        }
+        return SplitBitData();
+      }
+    }
+  }
+
   return false;
 }
 
+// TODO: Merge more of this with getTargetConstantBitsFromNode.
 static bool getTargetShuffleMaskIndices(SDValue MaskNode,
                                         unsigned MaskEltSizeInBits,
                                         SmallVectorImpl<uint64_t> &RawMask) {

Modified: llvm/trunk/test/CodeGen/X86/clear_upper_vector_element_bits.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/clear_upper_vector_element_bits.ll?rev=288499&r1=288498&r2=288499&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/clear_upper_vector_element_bits.ll (original)
+++ llvm/trunk/test/CodeGen/X86/clear_upper_vector_element_bits.ll Fri Dec  2 07:16:08 2016
@@ -41,17 +41,11 @@ define <4 x i32> @_clearupper4xi32a(<4 x
 ; SSE-NEXT:    andps {{.*}}(%rip), %xmm0
 ; SSE-NEXT:    retq
 ;
-; AVX1-LABEL: _clearupper4xi32a:
-; AVX1:       # BB#0:
-; AVX1-NEXT:    vpxor %xmm1, %xmm1, %xmm1
-; AVX1-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0],xmm1[1],xmm0[2],xmm1[3],xmm0[4],xmm1[5],xmm0[6],xmm1[7]
-; AVX1-NEXT:    retq
-;
-; AVX2-LABEL: _clearupper4xi32a:
-; AVX2:       # BB#0:
-; AVX2-NEXT:    vbroadcastss {{.*}}(%rip), %xmm1
-; AVX2-NEXT:    vandps %xmm1, %xmm0, %xmm0
-; AVX2-NEXT:    retq
+; AVX-LABEL: _clearupper4xi32a:
+; AVX:       # BB#0:
+; AVX-NEXT:    vpxor %xmm1, %xmm1, %xmm1
+; AVX-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0],xmm1[1],xmm0[2],xmm1[3],xmm0[4],xmm1[5],xmm0[6],xmm1[7]
+; AVX-NEXT:    retq
   %x0 = extractelement <4 x i32> %0, i32 0
   %x1 = extractelement <4 x i32> %0, i32 1
   %x2 = extractelement <4 x i32> %0, i32 2

Modified: llvm/trunk/test/CodeGen/X86/vec_int_to_fp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/vec_int_to_fp.ll?rev=288499&r1=288498&r2=288499&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/vec_int_to_fp.ll (original)
+++ llvm/trunk/test/CodeGen/X86/vec_int_to_fp.ll Fri Dec  2 07:16:08 2016
@@ -590,8 +590,8 @@ define <2 x double> @uitofp_4i32_to_2f64
 ; AVX2-NEXT:    vcvtdq2pd %xmm1, %ymm1
 ; AVX2-NEXT:    vbroadcastsd {{.*}}(%rip), %ymm2
 ; AVX2-NEXT:    vmulpd %ymm2, %ymm1, %ymm1
-; AVX2-NEXT:    vpbroadcastd {{.*}}(%rip), %xmm2
-; AVX2-NEXT:    vpand %xmm2, %xmm0, %xmm0
+; AVX2-NEXT:    vxorpd %xmm2, %xmm2, %xmm2
+; AVX2-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0],xmm2[1],xmm0[2],xmm2[3],xmm0[4],xmm2[5],xmm0[6],xmm2[7]
 ; AVX2-NEXT:    vcvtdq2pd %xmm0, %ymm0
 ; AVX2-NEXT:    vaddpd %ymm0, %ymm1, %ymm0
 ; AVX2-NEXT:    # kill: %XMM0<def> %XMM0<kill> %YMM0<kill>
@@ -889,8 +889,8 @@ define <4 x double> @uitofp_4i32_to_4f64
 ; AVX2-NEXT:    vcvtdq2pd %xmm1, %ymm1
 ; AVX2-NEXT:    vbroadcastsd {{.*}}(%rip), %ymm2
 ; AVX2-NEXT:    vmulpd %ymm2, %ymm1, %ymm1
-; AVX2-NEXT:    vpbroadcastd {{.*}}(%rip), %xmm2
-; AVX2-NEXT:    vpand %xmm2, %xmm0, %xmm0
+; AVX2-NEXT:    vxorpd %xmm2, %xmm2, %xmm2
+; AVX2-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0],xmm2[1],xmm0[2],xmm2[3],xmm0[4],xmm2[5],xmm0[6],xmm2[7]
 ; AVX2-NEXT:    vcvtdq2pd %xmm0, %ymm0
 ; AVX2-NEXT:    vaddpd %ymm0, %ymm1, %ymm0
 ; AVX2-NEXT:    retq
@@ -3274,8 +3274,8 @@ define <4 x double> @uitofp_load_4i32_to
 ; AVX2-NEXT:    vcvtdq2pd %xmm1, %ymm1
 ; AVX2-NEXT:    vbroadcastsd {{.*}}(%rip), %ymm2
 ; AVX2-NEXT:    vmulpd %ymm2, %ymm1, %ymm1
-; AVX2-NEXT:    vpbroadcastd {{.*}}(%rip), %xmm2
-; AVX2-NEXT:    vpand %xmm2, %xmm0, %xmm0
+; AVX2-NEXT:    vxorpd %xmm2, %xmm2, %xmm2
+; AVX2-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0],xmm2[1],xmm0[2],xmm2[3],xmm0[4],xmm2[5],xmm0[6],xmm2[7]
 ; AVX2-NEXT:    vcvtdq2pd %xmm0, %ymm0
 ; AVX2-NEXT:    vaddpd %ymm0, %ymm1, %ymm0
 ; AVX2-NEXT:    retq

Modified: llvm/trunk/test/CodeGen/X86/vec_uint_to_fp-fastmath.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/vec_uint_to_fp-fastmath.ll?rev=288499&r1=288498&r2=288499&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/vec_uint_to_fp-fastmath.ll (original)
+++ llvm/trunk/test/CodeGen/X86/vec_uint_to_fp-fastmath.ll Fri Dec  2 07:16:08 2016
@@ -26,9 +26,6 @@
 ; AVX2: [[FPMASKCSTADDR:.LCPI[0-9_]+]]:
 ; AVX2-NEXT: .long 1199570944 # float 65536
 
-; AVX2: [[MASKCSTADDR:.LCPI[0-9_]+]]:
-; AVX2-NEXT: .long 65535 # 0xffff
-
 define <4 x float> @test_uitofp_v4i32_to_v4f32(<4 x i32> %arg) {
 ; SSE2-LABEL: test_uitofp_v4i32_to_v4f32:
 ; SSE2:       # BB#0:
@@ -69,8 +66,8 @@ define <4 x float> @test_uitofp_v4i32_to
 ; AVX2-NEXT:    vcvtdq2ps %xmm1, %xmm1
 ; AVX2-NEXT:    vbroadcastss [[FPMASKCSTADDR]](%rip), %xmm2
 ; AVX2-NEXT:    vmulps %xmm2, %xmm1, %xmm1
-; AVX2-NEXT:    vpbroadcastd [[MASKCSTADDR]](%rip), %xmm2
-; AVX2-NEXT:    vpand %xmm2, %xmm0, %xmm0
+; AVX2-NEXT:    vxorps %xmm2, %xmm2, %xmm2
+; AVX2-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0],xmm2[1],xmm0[2],xmm2[3],xmm0[4],xmm2[5],xmm0[6],xmm2[7]
 ; AVX2-NEXT:    vcvtdq2ps %xmm0, %xmm0
 ; AVX2-NEXT:    vaddps %xmm0, %xmm1, %xmm0
 ; AVX2-NEXT:    retq




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