https://github.com/JonPsson1 created https://github.com/llvm/llvm-project/pull/176041
Add '-S64' to the SystemZ datalayout string, to avoid overalignment of stack objects. This changes 25 files on SPEC over 5 benchmarks, with fewer cases of runtime-alignment (NILL instructions). @uweigand @nikic >From 3410d910b8fcc943d736e7eff8d56aa2a09806fd Mon Sep 17 00:00:00 2001 From: Jonas Paulsson <[email protected]> Date: Wed, 14 Jan 2026 20:14:39 +0100 Subject: [PATCH] Add SP alignment to the DataLayout string. --- clang/test/CodeGen/target-data.c | 6 +++--- llvm/lib/TargetParser/TargetDataLayout.cpp | 3 +++ llvm/test/CodeGen/SystemZ/stack-align.ll | 17 +++++++++++++++++ 3 files changed, 23 insertions(+), 3 deletions(-) create mode 100644 llvm/test/CodeGen/SystemZ/stack-align.ll diff --git a/clang/test/CodeGen/target-data.c b/clang/test/CodeGen/target-data.c index e95079490bd3c..ee8e45511720c 100644 --- a/clang/test/CodeGen/target-data.c +++ b/clang/test/CodeGen/target-data.c @@ -207,11 +207,11 @@ // RUN: FileCheck %s -check-prefix=SYSTEMZ // RUN: %clang_cc1 -triple s390x-unknown -target-cpu z13 -target-feature +soft-float -o - -emit-llvm %s | \ // RUN: FileCheck %s -check-prefix=SYSTEMZ -// SYSTEMZ: target datalayout = "E-m:e-i1:8:16-i8:8:16-i64:64-f128:64-v128:64-a:8:16-n32:64" +// SYSTEMZ: target datalayout = "E-S64-m:e-i1:8:16-i8:8:16-i64:64-f128:64-v128:64-a:8:16-n32:64" // RUN: %clang_cc1 -triple s390x-unknown -target-cpu z13 -o - -emit-llvm %s | \ // RUN: FileCheck %s -check-prefix=SYSTEMZ-VECTOR -// SYSTEMZ-VECTOR: target datalayout = "E-m:e-i1:8:16-i8:8:16-i64:64-f128:64-v128:64-a:8:16-n32:64" +// SYSTEMZ-VECTOR: target datalayout = "E-S64-m:e-i1:8:16-i8:8:16-i64:64-f128:64-v128:64-a:8:16-n32:64" // RUN: %clang_cc1 -triple s390x-none-zos -target-cpu z10 -o - -emit-llvm %s | \ // RUN: FileCheck %s -check-prefix=ZOS @@ -219,7 +219,7 @@ // RUN: FileCheck %s -check-prefix=ZOS // RUN: %clang_cc1 -triple s390x-none-zos -target-cpu z13 -o - -emit-llvm %s | \ // RUN: FileCheck %s -check-prefix=ZOS -// ZOS: target datalayout = "E-m:l-p1:32:32-i1:8:16-i8:8:16-i64:64-f128:64-v128:64-a:8:16-n32:64" +// ZOS: target datalayout = "E-S64-m:l-p1:32:32-i1:8:16-i8:8:16-i64:64-f128:64-v128:64-a:8:16-n32:64" // RUN: %clang_cc1 -triple msp430-unknown -o - -emit-llvm %s | \ // RUN: FileCheck %s -check-prefix=MSP430 diff --git a/llvm/lib/TargetParser/TargetDataLayout.cpp b/llvm/lib/TargetParser/TargetDataLayout.cpp index b8c3b4325558c..b985c1eec4244 100644 --- a/llvm/lib/TargetParser/TargetDataLayout.cpp +++ b/llvm/lib/TargetParser/TargetDataLayout.cpp @@ -357,6 +357,9 @@ static std::string computeSystemZDataLayout(const Triple &TT) { // Big endian. Ret += "E"; + // The natural stack alignment is 64 bits. + Ret += "-S64"; + // Data mangling. Ret += getManglingComponent(TT); diff --git a/llvm/test/CodeGen/SystemZ/stack-align.ll b/llvm/test/CodeGen/SystemZ/stack-align.ll new file mode 100644 index 0000000000000..d7f6b1e8a46f2 --- /dev/null +++ b/llvm/test/CodeGen/SystemZ/stack-align.ll @@ -0,0 +1,17 @@ +; RUN: opt < %s -mtriple=s390x-unknown-linux-gnu -mcpu=z16 -S -passes=infer-alignment \ +; RUN: 2>&1 | FileCheck %s +; +; Test that the alignment of the alloca is not increased beyond the stack +; alignment of 8 bytes. + +declare void @foo(ptr) + +define void @f1(<4 x i64> %Arg) { +; CHECK-LABEL: define void @f1 +; CHECK-NEXT: %param = alloca <4 x i64>, align 8 +; CHECK-NEXT: store <4 x i64> %Arg, ptr %param, align 8 + %param = alloca <4 x i64>, align 8 + store <4 x i64> %Arg, ptr %param, align 8 + call void @foo(ptr %param) + ret void +} _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
