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

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Koakuma (koachan)

<details>
<summary>Changes</summary>

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).

---
Full diff: https://github.com/llvm/llvm-project/pull/106951.diff


4 Files Affected:

- (modified) clang/lib/Basic/Targets/Sparc.h (+3-3) 
- (modified) clang/test/CodeGen/target-data.c (+2-2) 
- (modified) llvm/lib/Target/Sparc/SparcTargetMachine.cpp (+4) 
- (added) llvm/test/CodeGen/SPARC/data-align.ll (+27) 


``````````diff
diff --git a/clang/lib/Basic/Targets/Sparc.h b/clang/lib/Basic/Targets/Sparc.h
index 3357bee33e1ac7..ee0d3e2b4329eb 100644
--- a/clang/lib/Basic/Targets/Sparc.h
+++ b/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 @@ class LLVM_LIBRARY_VISIBILITY SparcV9TargetInfo : public SparcTargetInfo {
   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;
 
diff --git a/clang/test/CodeGen/target-data.c b/clang/test/CodeGen/target-data.c
index 41cbd5a0219d5e..8548aa00cfe877 100644
--- a/clang/test/CodeGen/target-data.c
+++ b/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
diff --git a/llvm/lib/Target/Sparc/SparcTargetMachine.cpp b/llvm/lib/Target/Sparc/SparcTargetMachine.cpp
index fec2d3a35ae6d2..50a96368bbdca9 100644
--- a/llvm/lib/Target/Sparc/SparcTargetMachine.cpp
+++ b/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)
diff --git a/llvm/test/CodeGen/SPARC/data-align.ll b/llvm/test/CodeGen/SPARC/data-align.ll
new file mode 100644
index 00000000000000..d4a39524da44f6
--- /dev/null
+++ b/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
+ at i8 = private constant i8 42
+
+; CHECK:      .p2align 1
+; CHECK-NEXT: .Li16:
+; CHECK-DAG:  .size .Li16, 2
+ at i16 = private constant i16 42
+
+; CHECK:      .p2align 2
+; CHECK-NEXT: .Li32:
+; CHECK-DAG:  .size .Li32, 4
+ at i32 = private constant i32 42
+
+; CHECK:      .p2align 3
+; CHECK-NEXT: .Li64:
+; CHECK-DAG:  .size .Li64, 8
+ at i64 = private constant i64 42
+
+; CHECK:      .p2align 4
+; CHECK-NEXT: .Li128:
+; CHECK-DAG:  .size .Li128, 16
+ at i128 = private constant i128 42

``````````

</details>


https://github.com/llvm/llvm-project/pull/106951