Author: Harald van Dijk Date: 2020-12-12T17:05:24Z New Revision: f61e5ecb919b3901590328e69d3e4a557eefd788
URL: https://github.com/llvm/llvm-project/commit/f61e5ecb919b3901590328e69d3e4a557eefd788 DIFF: https://github.com/llvm/llvm-project/commit/f61e5ecb919b3901590328e69d3e4a557eefd788.diff LOG: [X86] Avoid data16 prefix for lea in x32 mode The ABI demands a data16 prefix for lea in 64-bit LP64 mode, but not in 64-bit ILP32 mode. In both modes this prefix would ordinarily be ignored, but the instructions may be changed by the linker to instructions that are affected by the prefix. Reviewed By: RKSimon Differential Revision: https://reviews.llvm.org/D93157 Added: Modified: llvm/lib/Target/X86/X86MCInstLower.cpp llvm/test/CodeGen/X86/pic.ll Removed: ################################################################################ diff --git a/llvm/lib/Target/X86/X86MCInstLower.cpp b/llvm/lib/Target/X86/X86MCInstLower.cpp index 6602d819929e..29faaa2dad36 100644 --- a/llvm/lib/Target/X86/X86MCInstLower.cpp +++ b/llvm/lib/Target/X86/X86MCInstLower.cpp @@ -979,6 +979,8 @@ void X86AsmPrinter::LowerTlsAddr(X86MCInstLower &MCInstLowering, NoAutoPaddingScope NoPadScope(*OutStreamer); bool Is64Bits = MI.getOpcode() != X86::TLS_addr32 && MI.getOpcode() != X86::TLS_base_addr32; + bool Is64BitsLP64 = MI.getOpcode() == X86::TLS_addr64 || + MI.getOpcode() == X86::TLS_base_addr64; MCContext &Ctx = OutStreamer->getContext(); MCSymbolRefExpr::VariantKind SRVK; @@ -1012,7 +1014,7 @@ void X86AsmPrinter::LowerTlsAddr(X86MCInstLower &MCInstLowering, if (Is64Bits) { bool NeedsPadding = SRVK == MCSymbolRefExpr::VK_TLSGD; - if (NeedsPadding) + if (NeedsPadding && Is64BitsLP64) EmitAndCountInstruction(MCInstBuilder(X86::DATA16_PREFIX)); EmitAndCountInstruction(MCInstBuilder(X86::LEA64r) .addReg(X86::RDI) diff --git a/llvm/test/CodeGen/X86/pic.ll b/llvm/test/CodeGen/X86/pic.ll index 3f3417e89ad8..101c749633bc 100644 --- a/llvm/test/CodeGen/X86/pic.ll +++ b/llvm/test/CodeGen/X86/pic.ll @@ -285,6 +285,7 @@ entry: ; CHECK-I686-DAG: calll ___tls_get_addr@PLT ; CHECK-I686-DAG: leal tlssrcgd@TLSGD(,%ebx), %eax ; CHECK-I686-DAG: calll ___tls_get_addr@PLT +; CHECK-X32-NOT: data16 ; CHECK-X32-DAG: leaq tlsdstgd@TLSGD(%rip), %rdi ; CHECK-X32-DAG: callq __tls_get_addr@PLT ; CHECK-X32-DAG: leaq tlsptrgd@TLSGD(%rip), %rdi _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
