[PowerPC] Use vector types for memcpy and friends (sometimes)

When using Altivec, we can use vector loads and stores for aligned memcpy and
friends. Starting with the P7 and VXS, we have reasonable unaligned vector
stores. Starting with the P8, we have fast unaligned loads too.

For QPX, we use vector loads are stores, but only for aligned memory accesses.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230788 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index 147e94b560a2333032400e12179c06a8b7262a6b..7de2ae10b8b8c9783cca1b693fde8295dcfe01bd 100644 (file)
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -892,6 +892,13 @@ PPCTargetLowering::PPCTargetLowering(const PPCTargetMachine &TM,
     MaxStoresPerMemcpyOptSize = 8;
     MaxStoresPerMemmove = 32;
     MaxStoresPerMemmoveOptSize = 8;
+  } else if (Subtarget.getDarwinDirective() == PPC::DIR_A2) {
+    // The A2 also benefits from (very) aggressive inlining of memcpy and
+    // friends. The overhead of a the function call, even when warm, can be
+    // over one hundred cycles.
+    MaxStoresPerMemset = 128;
+    MaxStoresPerMemcpy = 128;
+    MaxStoresPerMemmove = 128;
   }
 }
 
@@ -10914,11 +10921,27 @@ EVT PPCTargetLowering::getOptimalMemOpType(uint64_t Size,
                                            bool IsMemset, bool ZeroMemset,
                                            bool MemcpyStrSrc,
                                            MachineFunction &MF) const {
+  const Function *F = MF.getFunction();
+  // When expanding a memset, require at least two QPX instructions to cover
+  // the cost of loading the value to be stored from the constant pool.
+  if (Subtarget.hasQPX() && Size >= 32 && (!IsMemset || Size >= 64) &&
+     (!SrcAlign || SrcAlign >= 32) && (!DstAlign || DstAlign >= 32) &&
+      !F->hasFnAttribute(Attribute::NoImplicitFloat)) {
+    return MVT::v4f64;
+  }
+
+  // We should use Altivec/VSX loads and stores when available. For unaligned
+  // addresses, unaligned VSX loads are only fast starting with the P8.
+  if (Subtarget.hasAltivec() && Size >= 16 &&
+      (((!SrcAlign || SrcAlign >= 16) && (!DstAlign || DstAlign >= 16)) ||
+       ((IsMemset && Subtarget.hasVSX()) || Subtarget.hasP8Vector())))
+    return MVT::v4i32;
+
   if (Subtarget.isPPC64()) {
     return MVT::i64;
-  } else {
-    return MVT::i32;
   }
+
+  return MVT::i32;
 }
 
 /// \brief Returns true if it is beneficial to convert a load of a constant

diff --git a/test/CodeGen/PowerPC/memcpy-vec.ll b/test/CodeGen/PowerPC/memcpy-vec.ll
new file mode 100644 (file)
index 0000000..70b8ea9
--- /dev/null
+++ b/test/CodeGen/PowerPC/memcpy-vec.ll
@@ -0,0 +1,110 @@
+; RUN: llc -mcpu=pwr7 < %s | FileCheck %s -check-prefix=PWR7
+; RUN: llc -mcpu=pwr8 < %s | FileCheck %s -check-prefix=PWR8
+; RUN: llc -mcpu=a2q < %s | FileCheck %s -check-prefix=A2Q
+target datalayout = "E-m:e-i64:64-n32:64"
+target triple = "powerpc64-unknown-linux-gnu"
+
+; Function Attrs: nounwind
+define void @foo1(double* nocapture %x, double* nocapture readonly %y) #0 {
+entry:
+  %0 = bitcast double* %x to i8*
+  %1 = bitcast double* %y to i8*
+  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %0, i8* %1, i64 32, i32 8, i1 false)
+  ret void
+
+; PWR7-LABEL: @foo1
+; PWR7-NOT: bl memcpy
+; PWR7: ld {{[0-9]+}}, {{[0-9]+}}(4)
+; PWR7: std {{[0-9]+}}, {{[0-9]+}}(3)
+; PWR7: blr
+
+; PWR8-LABEL: @foo1
+; PWR8: lxvw4x
+; PWR8: stxvw4x
+; PWR8: blr
+
+; A2Q-LABEL: @foo1
+; A2Q-NOT: bl memcpy
+; A2Q: ld {{[0-9]+}}, {{[0-9]+}}(4)
+; A2Q: std {{[0-9]+}}, {{[0-9]+}}(3)
+; A2Q: blr
+}
+
+; Function Attrs: nounwind
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i32, i1) #0
+
+; Function Attrs: nounwind
+define void @foo2(double* nocapture %x, double* nocapture readonly %y) #0 {
+entry:
+  %0 = bitcast double* %x to i8*
+  %1 = bitcast double* %y to i8*
+  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %0, i8* %1, i64 128, i32 8, i1 false)
+  ret void
+
+; PWR7-LABEL: @foo2
+; PWR7: bl memcpy
+; PWR7: blr
+
+; PWR8-LABEL: @foo2
+; PWR8: lxvw4x
+; PWR8: stxvw4x
+; PWR8: blr
+
+; A2Q-LABEL: @foo2
+; A2Q-NOT: bl memcpy
+; A2Q: ld {{[0-9]+}}, {{[0-9]+}}(4)
+; A2Q: std {{[0-9]+}}, {{[0-9]+}}(3)
+; A2Q: blr
+}
+
+; Function Attrs: nounwind
+define void @bar1(double* nocapture %x) #0 {
+entry:
+  %0 = bitcast double* %x to i8*
+  tail call void @llvm.memset.p0i8.i64(i8* %0, i8 0, i64 128, i32 8, i1 false)
+  ret void
+
+; PWR7-LABEL: @bar1
+; PWR7-NOT: bl memset
+; PWR7: stxvw4x
+; PWR7: blr
+
+; PWR8-LABEL: @bar1
+; PWR8-NOT: bl memset
+; PWR8: stxvw4x
+; PWR8: blr
+
+; A2Q-LABEL: @bar1
+; A2Q-NOT: bl memset
+; A2Q: std {{[0-9]+}}, {{[0-9]+}}(3)
+; A2Q: blr
+}
+
+; Function Attrs: nounwind
+define void @bar2(double* nocapture %x) #0 {
+entry:
+  %0 = bitcast double* %x to i8*
+  tail call void @llvm.memset.p0i8.i64(i8* %0, i8 0, i64 128, i32 32, i1 false)
+  ret void
+
+; PWR7-LABEL: @bar2
+; PWR7-NOT: bl memset
+; PWR7: stxvw4x
+; PWR7: blr
+
+; PWR8-LABEL: @bar2
+; PWR8-NOT: bl memset
+; PWR8: stxvw4x
+; PWR8: blr
+
+; A2Q-LABEL: @bar2
+; A2Q-NOT: bl memset
+; A2Q: qvstfdx
+; A2Q: blr
+}
+
+; Function Attrs: nounwind
+declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) #0
+
+attributes #0 = { nounwind }
+

diff --git a/test/CodeGen/PowerPC/ppc64-byval-align.ll b/test/CodeGen/PowerPC/ppc64-byval-align.ll
index a4d5c2a72d4c28129fca8c748f6a238be9cdad3a..be1c502270074c61404f18cc8b46533f8de43e41 100644 (file)
--- a/test/CodeGen/PowerPC/ppc64-byval-align.ll
+++ b/test/CodeGen/PowerPC/ppc64-byval-align.ll
@@ -50,7 +50,9 @@ entry:
 }
 ; CHECK-LABEL: @caller2
 ; CHECK: std 3, [[OFF:[0-9]+]](1)
-; CHECK: ld [[REG:[0-9]+]], [[OFF]](1)
-; CHECK: std [[REG]], 128(1)
+; CHECK: addi [[REG1:[0-9]+]], 1, [[OFF]]
+; CHECK: lxvw4x [[REG2:[0-9]+]], 0, [[REG1]]
+; CHECK: li [[REG3:[0-9]+]], 128
+; CHECK: stxvw4x 0, 1, [[REG3]]
 ; CHECK: bl test2