[clang] [llvm] [PowerPC] Take ABI into account for data layout (PR #149725)
Jens Reidel via cfe-commits
cfe-commits at lists.llvm.org
Wed Oct 29 13:55:09 PDT 2025
https://github.com/Gelbpunkt updated https://github.com/llvm/llvm-project/pull/149725
>From d044da8a9d7885694b141a10d7ce96053892beab Mon Sep 17 00:00:00 2001
From: Jens Reidel <adrian at travitia.xyz>
Date: Sun, 20 Jul 2025 19:10:13 +0200
Subject: [PATCH] [PowerPC] Take ABI into account for data layout
Prior to this change, the data layout calculation would not account for
explicitly set -mabi=elfv2 on powerpc64-unknown-linux-gnu, a target that
defaults to elfv1.
Signed-off-by: Jens Reidel <adrian at travitia.xyz>
---
clang/lib/Basic/Targets/PPC.h | 45 ++++++++++++-------
.../PowerPC/ppc64-abi-override-datalayout.c | 8 ++++
llvm/lib/Target/PowerPC/PPCTargetMachine.cpp | 5 ++-
llvm/lib/TargetParser/TargetDataLayout.cpp | 7 +--
4 files changed, 43 insertions(+), 22 deletions(-)
create mode 100644 clang/test/CodeGen/PowerPC/ppc64-abi-override-datalayout.c
diff --git a/clang/lib/Basic/Targets/PPC.h b/clang/lib/Basic/Targets/PPC.h
index 846b240218172..d2eb9c5e12a90 100644
--- a/clang/lib/Basic/Targets/PPC.h
+++ b/clang/lib/Basic/Targets/PPC.h
@@ -445,27 +445,17 @@ class LLVM_LIBRARY_VISIBILITY PPC64TargetInfo : public PPCTargetInfo {
LongWidth = LongAlign = PointerWidth = PointerAlign = 64;
IntMaxType = SignedLong;
Int64Type = SignedLong;
- std::string DataLayout;
if (Triple.isOSAIX()) {
// TODO: Set appropriate ABI for AIX platform.
- DataLayout = "E-m:a-Fi64-i64:64-i128:128-n32:64";
LongDoubleWidth = 64;
LongDoubleAlign = DoubleAlign = 32;
LongDoubleFormat = &llvm::APFloat::IEEEdouble();
- } else if ((Triple.getArch() == llvm::Triple::ppc64le)) {
- DataLayout = "e-m:e-Fn32-i64:64-i128:128-n32:64";
+ } else if ((Triple.getArch() == llvm::Triple::ppc64le) ||
+ Triple.isPPC64ELFv2ABI()) {
ABI = "elfv2";
} else {
- DataLayout = "E-m:e";
- if (Triple.isPPC64ELFv2ABI()) {
- ABI = "elfv2";
- DataLayout += "-Fn32";
- } else {
- ABI = "elfv1";
- DataLayout += "-Fi64";
- }
- DataLayout += "-i64:64-i128:128-n32:64";
+ ABI = "elfv1";
}
if (Triple.isOSFreeBSD() || Triple.isOSOpenBSD() || Triple.isMusl()) {
@@ -473,14 +463,12 @@ class LLVM_LIBRARY_VISIBILITY PPC64TargetInfo : public PPCTargetInfo {
LongDoubleFormat = &llvm::APFloat::IEEEdouble();
}
- if (Triple.isOSAIX() || Triple.isOSLinux())
- DataLayout += "-S128-v256:256:256-v512:512:512";
- resetDataLayout(DataLayout);
-
// Newer PPC64 instruction sets support atomics up to 16 bytes.
MaxAtomicPromoteWidth = 128;
// Baseline PPC64 supports inlining atomics up to 8 bytes.
MaxAtomicInlineWidth = 64;
+
+ calculateDataLayout();
}
void setMaxAtomicWidth() override {
@@ -495,10 +483,33 @@ class LLVM_LIBRARY_VISIBILITY PPC64TargetInfo : public PPCTargetInfo {
return TargetInfo::CharPtrBuiltinVaList;
}
+ void calculateDataLayout() {
+ std::string DataLayout;
+
+ if (getTriple().isOSAIX()) {
+ DataLayout = "E-m:a-Fi64-i64:64-i128:128-n32:64";
+ } else if ((getTriple().getArch() == llvm::Triple::ppc64le)) {
+ DataLayout = "e-m:e-Fn32-i64:64-i128:128-n32:64";
+ } else {
+ DataLayout = "E-m:e";
+ if (ABI == "elfv2") {
+ DataLayout += "-Fn32";
+ } else {
+ DataLayout += "-Fi64";
+ }
+ DataLayout += "-i64:64-i128:128-n32:64";
+ }
+
+ if (getTriple().isOSAIX() || getTriple().isOSLinux())
+ DataLayout += "-S128-v256:256:256-v512:512:512";
+ resetDataLayout(DataLayout);
+ }
+
// PPC64 Linux-specific ABI options.
bool setABI(const std::string &Name) override {
if (Name == "elfv1" || Name == "elfv2") {
ABI = Name;
+ calculateDataLayout();
return true;
}
return false;
diff --git a/clang/test/CodeGen/PowerPC/ppc64-abi-override-datalayout.c b/clang/test/CodeGen/PowerPC/ppc64-abi-override-datalayout.c
new file mode 100644
index 0000000000000..30b85d24a56fd
--- /dev/null
+++ b/clang/test/CodeGen/PowerPC/ppc64-abi-override-datalayout.c
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -triple powerpc64-unknown-linux-gnu -target-abi elfv2 %s -o - -emit-llvm | FileCheck %s
+
+// REQUIRES: powerpc-registered-target
+
+// Make sure that overriding the ABI to ELFv2 on a target that defaults to
+// ELFv1 changes the data layout:
+
+// CHECK: target datalayout = "E-m:e-Fn32-i64:64-i128:128-n32:64-S128-v256:256:256-v512:512:512"
diff --git a/llvm/lib/Target/PowerPC/PPCTargetMachine.cpp b/llvm/lib/Target/PowerPC/PPCTargetMachine.cpp
index 000d29610678f..4ff489d482fa5 100644
--- a/llvm/lib/Target/PowerPC/PPCTargetMachine.cpp
+++ b/llvm/lib/Target/PowerPC/PPCTargetMachine.cpp
@@ -296,8 +296,9 @@ PPCTargetMachine::PPCTargetMachine(const Target &T, const Triple &TT,
std::optional<Reloc::Model> RM,
std::optional<CodeModel::Model> CM,
CodeGenOptLevel OL, bool JIT)
- : CodeGenTargetMachineImpl(T, TT.computeDataLayout(), TT, CPU,
- computeFSAdditions(FS, OL, TT), Options,
+ : CodeGenTargetMachineImpl(T,
+ TT.computeDataLayout(Options.MCOptions.ABIName),
+ TT, CPU, computeFSAdditions(FS, OL, TT), Options,
getEffectiveRelocModel(TT, RM),
getEffectivePPCCodeModel(TT, CM, JIT), OL),
TLOF(createTLOF(getTargetTriple())),
diff --git a/llvm/lib/TargetParser/TargetDataLayout.cpp b/llvm/lib/TargetParser/TargetDataLayout.cpp
index d765d9ccb284d..d7359234b02f7 100644
--- a/llvm/lib/TargetParser/TargetDataLayout.cpp
+++ b/llvm/lib/TargetParser/TargetDataLayout.cpp
@@ -208,7 +208,7 @@ static std::string computeMipsDataLayout(const Triple &TT, StringRef ABIName) {
return Ret;
}
-static std::string computePowerDataLayout(const Triple &T) {
+static std::string computePowerDataLayout(const Triple &T, StringRef ABIName) {
bool is64Bit = T.isPPC64();
std::string Ret;
@@ -228,7 +228,8 @@ static std::string computePowerDataLayout(const Triple &T) {
// If the target ABI uses function descriptors, then the alignment of function
// pointers depends on the alignment used to emit the descriptor. Otherwise,
// function pointers are aligned to 32 bits because the instructions must be.
- if ((T.getArch() == Triple::ppc64 && !T.isPPC64ELFv2ABI())) {
+ if ((T.getArch() == Triple::ppc64 &&
+ (!T.isPPC64ELFv2ABI() && ABIName != "elfv2"))) {
Ret += "-Fi64";
} else if (T.isOSAIX()) {
Ret += is64Bit ? "-Fi64" : "-Fi32";
@@ -573,7 +574,7 @@ std::string Triple::computeDataLayout(StringRef ABIName) const {
case Triple::ppcle:
case Triple::ppc64:
case Triple::ppc64le:
- return computePowerDataLayout(*this);
+ return computePowerDataLayout(*this, ABIName);
case Triple::r600:
case Triple::amdgcn:
return computeAMDDataLayout(*this);
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