[lld] [llvm] [LTO] Override TargetABI from module flags if present when creating TargetMachine (PR #126497)
Kito Cheng via llvm-commits
llvm-commits at lists.llvm.org
Thu Mar 6 19:54:16 PST 2025
https://github.com/kito-cheng updated https://github.com/llvm/llvm-project/pull/126497
>From 17294049967f003a7ed845fe91b8828443b815ea Mon Sep 17 00:00:00 2001
From: Kito Cheng <kito.cheng at sifive.com>
Date: Mon, 10 Feb 2025 00:57:03 -0800
Subject: [PATCH 1/6] [LTO] Override TargetABI from module flags if present
when creating TargetMachine
RISC-V's data layout is also determined by the ABI, not only the target triple,
however the TargetMachine is created with the target triple's data layout,
that is not always correct. This patch changes the TargetMachine's data
layout to the one specified in the module flags if present.
The same problem will happen with other targets like MIPS, but unfortunately,
MIPS didn't emit the target-abi into the module flags, so this patch only
fixes the issue for RISC-V.
NOTE: MIPS with -mabi=n32 can trigger the same issue.
Another possible solution is add new parameter to the TargetMachine
constructor, but that would require changes in all the targets.
---
lld/test/ELF/lto/riscv-ilp32e.ll | 25 +++++++++++++++++++++++++
llvm/lib/LTO/LTOBackend.cpp | 12 +++++++++++-
2 files changed, 36 insertions(+), 1 deletion(-)
create mode 100644 lld/test/ELF/lto/riscv-ilp32e.ll
diff --git a/lld/test/ELF/lto/riscv-ilp32e.ll b/lld/test/ELF/lto/riscv-ilp32e.ll
new file mode 100644
index 0000000000000..ea2b57d483358
--- /dev/null
+++ b/lld/test/ELF/lto/riscv-ilp32e.ll
@@ -0,0 +1,25 @@
+; REQUIRES: riscv
+;
+; Check that we don't crash on DataLayout incompatibility issue.
+;
+; RUN: llvm-as %s -o %t.o
+; RUN: ld.lld %t.o -o %t.elf
+; RUN: llvm-readobj -h %t.elf | FileCheck %s --check-prefixes=CHECK
+;
+; CHECK: Machine: EM_RISCV (0xF3)
+; CHECK: EF_RISCV_RVE (0x8)
+
+
+target datalayout = "e-m:e-p:32:32-i64:64-n32-S32"
+target triple = "riscv32-unknown-unknown-elf"
+
+define dso_local i32 @_start() #0 {
+entry:
+ ret i32 0
+}
+
+attributes #0 = { "target-cpu"="generic-rv32" "target-features"="+32bit,+e" }
+
+!llvm.module.flags = !{!0}
+
+!0 = !{i32 1, !"target-abi", !"ilp32e"}
diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
index b38252a3272e8..daec55f02d62a 100644
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -221,8 +221,18 @@ createTargetMachine(const Config &Conf, const Target *TheTarget, Module &M) {
else
CodeModel = M.getCodeModel();
+ TargetOptions TargetOpts = Conf.Options;
+
+ if (TargetOpts.MCOptions.ABIName.empty()) {
+ Metadata *ABI = M.getModuleFlag("target-abi");
+ if (ABI) {
+ const StringRef &ModABI = cast<MDString>(ABI)->getString();
+ TargetOpts.MCOptions.ABIName = ModABI;
+ }
+ }
+
std::unique_ptr<TargetMachine> TM(TheTarget->createTargetMachine(
- TheTriple.str(), Conf.CPU, Features.getString(), Conf.Options, RelocModel,
+ TheTriple.str(), Conf.CPU, Features.getString(), TargetOpts, RelocModel,
CodeModel, Conf.CGOptLevel));
assert(TM && "Failed to create target machine");
>From ccffce3edb94b52bc7d65ab1522928d578f03f4e Mon Sep 17 00:00:00 2001
From: Kito Cheng <kito.cheng at sifive.com>
Date: Wed, 12 Feb 2025 00:47:55 -0800
Subject: [PATCH 2/6] address comment
---
llvm/test/LTO/RISCV/lit.local.cfg | 2 ++
{lld/test/ELF/lto => llvm/test/LTO/RISCV}/riscv-ilp32e.ll | 6 ++----
2 files changed, 4 insertions(+), 4 deletions(-)
create mode 100644 llvm/test/LTO/RISCV/lit.local.cfg
rename {lld/test/ELF/lto => llvm/test/LTO/RISCV}/riscv-ilp32e.ll (79%)
diff --git a/llvm/test/LTO/RISCV/lit.local.cfg b/llvm/test/LTO/RISCV/lit.local.cfg
new file mode 100644
index 0000000000000..17351748513d9
--- /dev/null
+++ b/llvm/test/LTO/RISCV/lit.local.cfg
@@ -0,0 +1,2 @@
+if not "RISCV" in config.root.targets:
+ config.unsupported = True
diff --git a/lld/test/ELF/lto/riscv-ilp32e.ll b/llvm/test/LTO/RISCV/riscv-ilp32e.ll
similarity index 79%
rename from lld/test/ELF/lto/riscv-ilp32e.ll
rename to llvm/test/LTO/RISCV/riscv-ilp32e.ll
index ea2b57d483358..45cc1b78f649a 100644
--- a/lld/test/ELF/lto/riscv-ilp32e.ll
+++ b/llvm/test/LTO/RISCV/riscv-ilp32e.ll
@@ -1,10 +1,8 @@
-; REQUIRES: riscv
-;
; Check that we don't crash on DataLayout incompatibility issue.
;
; RUN: llvm-as %s -o %t.o
-; RUN: ld.lld %t.o -o %t.elf
-; RUN: llvm-readobj -h %t.elf | FileCheck %s --check-prefixes=CHECK
+; RUN: llvm-lto2 run -r %t.o,_start %t.o -o %t.elf
+; RUN: llvm-readobj -h %t.elf.0 | FileCheck %s --check-prefixes=CHECK
;
; CHECK: Machine: EM_RISCV (0xF3)
; CHECK: EF_RISCV_RVE (0x8)
>From 45a7e9db5e17610e948f7ae0ca8f8a7f98293ce1 Mon Sep 17 00:00:00 2001
From: Kito Cheng <kito.cheng at sifive.com>
Date: Mon, 3 Mar 2025 22:48:35 +0800
Subject: [PATCH 3/6] Add Module::getTargetABIFromMD
---
llvm/include/llvm/IR/Module.h | 3 +++
llvm/lib/IR/Module.cpp | 8 ++++++++
llvm/lib/LTO/LTOBackend.cpp | 5 ++---
3 files changed, 13 insertions(+), 3 deletions(-)
diff --git a/llvm/include/llvm/IR/Module.h b/llvm/include/llvm/IR/Module.h
index 2fd2d6887022c..91ccd76c41e07 100644
--- a/llvm/include/llvm/IR/Module.h
+++ b/llvm/include/llvm/IR/Module.h
@@ -1067,6 +1067,9 @@ class LLVM_ABI Module {
/// Set the target variant version build SDK version metadata.
void setDarwinTargetVariantSDKVersion(VersionTuple Version);
+
+ /// Returns target-abi from MDString, null if target-abi is absent.
+ StringRef getTargetABIFromMD();
};
/// Given "llvm.used" or "llvm.compiler.used" as a global name, collect the
diff --git a/llvm/lib/IR/Module.cpp b/llvm/lib/IR/Module.cpp
index c7b9f8744d8d3..3ee53528a825e 100644
--- a/llvm/lib/IR/Module.cpp
+++ b/llvm/lib/IR/Module.cpp
@@ -915,3 +915,11 @@ VersionTuple Module::getDarwinTargetVariantSDKVersion() const {
void Module::setDarwinTargetVariantSDKVersion(VersionTuple Version) {
addSDKVersionMD(Version, *this, "darwin.target_variant.SDK Version");
}
+
+StringRef Module::getTargetABIFromMD() {
+ StringRef TargetABI = "";
+ if (auto *TargetABIMD =
+ dyn_cast_or_null<MDString>(getModuleFlag("target-abi")))
+ TargetABI = TargetABIMD->getString();
+ return TargetABI;
+}
diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
index daec55f02d62a..3964e1cdb53d8 100644
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -224,9 +224,8 @@ createTargetMachine(const Config &Conf, const Target *TheTarget, Module &M) {
TargetOptions TargetOpts = Conf.Options;
if (TargetOpts.MCOptions.ABIName.empty()) {
- Metadata *ABI = M.getModuleFlag("target-abi");
- if (ABI) {
- const StringRef &ModABI = cast<MDString>(ABI)->getString();
+ StringRef ModABI = M.getTargetABIFromMD();
+ if (!ABI.empty()) {
TargetOpts.MCOptions.ABIName = ModABI;
}
}
>From a6e8f5dbfc73f5becf2de4a106b89c8a69ba1dd2 Mon Sep 17 00:00:00 2001
From: Kito Cheng <kito.cheng at sifive.com>
Date: Mon, 3 Mar 2025 22:56:00 +0800
Subject: [PATCH 4/6] fix build fail
---
llvm/lib/LTO/LTOBackend.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
index 3964e1cdb53d8..1795faa577cbe 100644
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -225,7 +225,7 @@ createTargetMachine(const Config &Conf, const Target *TheTarget, Module &M) {
if (TargetOpts.MCOptions.ABIName.empty()) {
StringRef ModABI = M.getTargetABIFromMD();
- if (!ABI.empty()) {
+ if (!ModABI.empty()) {
TargetOpts.MCOptions.ABIName = ModABI;
}
}
>From 1d613812ca56439102ccce55ddb9e338fb4c4bb8 Mon Sep 17 00:00:00 2001
From: Kito Cheng <kito.cheng at sifive.com>
Date: Fri, 7 Mar 2025 11:43:20 +0800
Subject: [PATCH 5/6] Address MaskRay's comment
---
llvm/lib/IR/Module.cpp | 2 +-
llvm/lib/LTO/LTOBackend.cpp | 1 -
llvm/test/LTO/RISCV/lit.local.cfg | 2 +-
llvm/test/LTO/RISCV/riscv-ilp32e.ll | 2 --
4 files changed, 2 insertions(+), 5 deletions(-)
diff --git a/llvm/lib/IR/Module.cpp b/llvm/lib/IR/Module.cpp
index 3ee53528a825e..c7daaafe13e3f 100644
--- a/llvm/lib/IR/Module.cpp
+++ b/llvm/lib/IR/Module.cpp
@@ -917,7 +917,7 @@ void Module::setDarwinTargetVariantSDKVersion(VersionTuple Version) {
}
StringRef Module::getTargetABIFromMD() {
- StringRef TargetABI = "";
+ StringRef TargetABI;
if (auto *TargetABIMD =
dyn_cast_or_null<MDString>(getModuleFlag("target-abi")))
TargetABI = TargetABIMD->getString();
diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
index 1795faa577cbe..10393b777d855 100644
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -222,7 +222,6 @@ createTargetMachine(const Config &Conf, const Target *TheTarget, Module &M) {
CodeModel = M.getCodeModel();
TargetOptions TargetOpts = Conf.Options;
-
if (TargetOpts.MCOptions.ABIName.empty()) {
StringRef ModABI = M.getTargetABIFromMD();
if (!ModABI.empty()) {
diff --git a/llvm/test/LTO/RISCV/lit.local.cfg b/llvm/test/LTO/RISCV/lit.local.cfg
index 17351748513d9..a3d2298159063 100644
--- a/llvm/test/LTO/RISCV/lit.local.cfg
+++ b/llvm/test/LTO/RISCV/lit.local.cfg
@@ -1,2 +1,2 @@
-if not "RISCV" in config.root.targets:
+if "RISCV" not in config.root.targets:
config.unsupported = True
diff --git a/llvm/test/LTO/RISCV/riscv-ilp32e.ll b/llvm/test/LTO/RISCV/riscv-ilp32e.ll
index 45cc1b78f649a..bbca58e65556d 100644
--- a/llvm/test/LTO/RISCV/riscv-ilp32e.ll
+++ b/llvm/test/LTO/RISCV/riscv-ilp32e.ll
@@ -1,9 +1,7 @@
; Check that we don't crash on DataLayout incompatibility issue.
-;
; RUN: llvm-as %s -o %t.o
; RUN: llvm-lto2 run -r %t.o,_start %t.o -o %t.elf
; RUN: llvm-readobj -h %t.elf.0 | FileCheck %s --check-prefixes=CHECK
-;
; CHECK: Machine: EM_RISCV (0xF3)
; CHECK: EF_RISCV_RVE (0x8)
>From c1c590555f2a2d61178ca16eb671193b74cff3c1 Mon Sep 17 00:00:00 2001
From: Kito Cheng <kito.cheng at gmail.com>
Date: Fri, 7 Mar 2025 11:54:07 +0800
Subject: [PATCH 6/6] Update llvm/lib/LTO/LTOBackend.cpp
Co-authored-by: Alexander Richardson <mail at alexrichardson.me>
---
llvm/lib/LTO/LTOBackend.cpp | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
index 10393b777d855..139c39abf8e6b 100644
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -223,10 +223,7 @@ createTargetMachine(const Config &Conf, const Target *TheTarget, Module &M) {
TargetOptions TargetOpts = Conf.Options;
if (TargetOpts.MCOptions.ABIName.empty()) {
- StringRef ModABI = M.getTargetABIFromMD();
- if (!ModABI.empty()) {
- TargetOpts.MCOptions.ABIName = ModABI;
- }
+ TargetOpts.MCOptions.ABIName = M.getTargetABIFromMD();
}
std::unique_ptr<TargetMachine> TM(TheTarget->createTargetMachine(
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