[SPARC] Align i128 to 16 bytes in SPARC datalayouts (#106951)

Align i128s to 16 bytes, following the example at
https://reviews.llvm.org/D86310.

clang already does this implicitly, but do it in backend code too for
the benefit of other frontends (see e.g
https://github.com/llvm/llvm-project/issues/102783 &
https://github.com/rust-lang/rust/issues/128950).

clang/lib/Basic/Targets/Sparc.h

@@ -151,7 +151,7 @@ class LLVM_LIBRARY_VISIBILITY SparcV8TargetInfo : public SparcTargetInfo {
 public:
   SparcV8TargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
       : SparcTargetInfo(Triple, Opts) {
-    resetDataLayout("E-m:e-p:32:32-i64:64-f128:64-n32-S64");
+    resetDataLayout("E-m:e-p:32:32-i64:64-i128:128-f128:64-n32-S64");
     // NetBSD / OpenBSD use long (same as llvm default); everyone else uses int.
     switch (getTriple().getOS()) {
     default:
@@ -188,7 +188,7 @@ class LLVM_LIBRARY_VISIBILITY SparcV8elTargetInfo : public SparcV8TargetInfo {
 public:
   SparcV8elTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
       : SparcV8TargetInfo(Triple, Opts) {
-    resetDataLayout("e-m:e-p:32:32-i64:64-f128:64-n32-S64");
+    resetDataLayout("e-m:e-p:32:32-i64:64-i128:128-f128:64-n32-S64");
   }
 };
 
@@ -198,7 +198,7 @@ public:
   SparcV9TargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
       : SparcTargetInfo(Triple, Opts) {
     // FIXME: Support Sparc quad-precision long double?
-    resetDataLayout("E-m:e-i64:64-n32:64-S128");
+    resetDataLayout("E-m:e-i64:64-i128:128-n32:64-S128");
     // This is an LP64 platform.
     LongWidth = LongAlign = PointerWidth = PointerAlign = 64;
 

clang/test/CodeGen/target-data.c

@@ -28,11 +28,11 @@
 
 // RUN: %clang_cc1 -triple sparc-sun-solaris -emit-llvm -o - %s | \
 // RUN:     FileCheck %s --check-prefix=SPARC-V8
-// SPARC-V8: target datalayout = "E-m:e-p:32:32-i64:64-f128:64-n32-S64"
+// SPARC-V8: target datalayout = "E-m:e-p:32:32-i64:64-i128:128-f128:64-n32-S64"
 
 // RUN: %clang_cc1 -triple sparcv9-sun-solaris -emit-llvm -o - %s | \
 // RUN: FileCheck %s --check-prefix=SPARC-V9
-// SPARC-V9: target datalayout = "E-m:e-i64:64-n32:64-S128"
+// SPARC-V9: target datalayout = "E-m:e-i64:64-i128:128-n32:64-S128"
 
 // RUN: %clang_cc1 -triple mipsel-linux-gnu -o - -emit-llvm %s |     \
 // RUN: FileCheck %s -check-prefix=MIPS-32EL

llvm/lib/IR/AutoUpgrade.cpp

@@ -5517,6 +5517,18 @@ std::string llvm::UpgradeDataLayoutString(StringRef DL, StringRef TT) {
     return Res;
   }
 
+  if (T.isSPARC()) {
+    // Add "-i128:128"
+    std::string I64 = "-i64:64";
+    std::string I128 = "-i128:128";
+    if (!StringRef(Res).contains(I128)) {
+      size_t Pos = Res.find(I64);
+      assert(Pos != size_t(-1) && "no i64 data layout found!");
+      Res.insert(Pos + I64.size(), I128);
+    }
+    return Res;
+  }
+
   if (!T.isX86())
     return Res;
 

llvm/lib/Target/Sparc/SparcTargetMachine.cpp

@@ -48,6 +48,10 @@ static std::string computeDataLayout(const Triple &T, bool is64Bit) {
   // Alignments for 64 bit integers.
   Ret += "-i64:64";
 
+  // Alignments for 128 bit integers.
+  // This is not specified in the ABI document but is the de facto standard.
+  Ret += "-i128:128";
+
   // On SparcV9 128 floats are aligned to 128 bits, on others only to 64.
   // On SparcV9 registers can hold 64 or 32 bits, on others only 32.
   if (is64Bit)

llvm/test/CodeGen/SPARC/data-align.ll

@@ -0,0 +1,27 @@
+; RUN: llc < %s -march=sparc | FileCheck %s
+; RUN: llc < %s -march=sparcel | FileCheck %s
+; RUN: llc < %s -march=sparcv9 | FileCheck %s
+
+; CHECK:      .Li8:
+; CHECK-DAG: .size .Li8, 1
+@i8 = private constant i8 42
+
+; CHECK:      .p2align 1
+; CHECK-NEXT: .Li16:
+; CHECK-DAG:  .size .Li16, 2
+@i16 = private constant i16 42
+
+; CHECK:      .p2align 2
+; CHECK-NEXT: .Li32:
+; CHECK-DAG:  .size .Li32, 4
+@i32 = private constant i32 42
+
+; CHECK:      .p2align 3
+; CHECK-NEXT: .Li64:
+; CHECK-DAG:  .size .Li64, 8
+@i64 = private constant i64 42
+
+; CHECK:      .p2align 4
+; CHECK-NEXT: .Li128:
+; CHECK-DAG:  .size .Li128, 16
+@i128 = private constant i128 42

llvm/unittests/Bitcode/DataLayoutUpgradeTest.cpp

@@ -68,6 +68,13 @@ TEST(DataLayoutUpgradeTest, ValidDataLayoutUpgrade) {
                                     "loongarch64"),
             "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128");
 
+  // Check that SPARC targets add -i128:128.
+  EXPECT_EQ(
+      UpgradeDataLayoutString("E-m:e-p:32:32-i64:64-f128:64-n32-S64", "sparc"),
+      "E-m:e-p:32:32-i64:64-i128:128-f128:64-n32-S64");
+  EXPECT_EQ(UpgradeDataLayoutString("E-m:e-i64:64-n32:64-S128", "sparcv9"),
+            "E-m:e-i64:64-i128:128-n32:64-S128");
+
   // Check that SPIR && SPIRV targets add -G1 if it's not present.
   EXPECT_EQ(UpgradeDataLayoutString("e-p:32:32", "spir"), "e-p:32:32-G1");
   EXPECT_EQ(UpgradeDataLayoutString("e-p:32:32", "spir64"), "e-p:32:32-G1");