Printing the raw symbol is useful in inline asm (e.g. in C++ to get the mangled name). Similar constraints are available in other targets (e.g. "S" for aarch64/riscv, "Cs" for m68k).
There isn't a good way for x86 yet, e.g. "i" doesn't work for PIC/-mcmodel=large. This patch adds "Ws". Here are possible use cases: ``` namespace ns { extern int var; } asm (".pushsection .xxx,\"aw\"; .dc.a %0; .popsection" :: "Ws"(&var)); asm (".reloc ., BFD_RELOC_NONE, %0" :: "Ws"(&var)); ``` gcc/ChangeLog: PR target/105576 * config/i386/constraints.md: Define constraint "Ws". * doc/md.texi: Document it. gcc/testsuite/ChangeLog: * gcc.target/i386/asm-raw-symbol.c: New testcase. --- This obsoletes https://gcc.gnu.org/pipermail/gcc-patches/2024-January/642580.html I initially tried 'z', but Uros requested that a W prefix is used. --- gcc/config/i386/constraints.md | 4 ++++ gcc/doc/md.texi | 4 ++++ gcc/testsuite/gcc.target/i386/asm-raw-symbol.c | 13 +++++++++++++ 3 files changed, 21 insertions(+) create mode 100644 gcc/testsuite/gcc.target/i386/asm-raw-symbol.c diff --git a/gcc/config/i386/constraints.md b/gcc/config/i386/constraints.md index 0c6e662df25..280e4c8e36c 100644 --- a/gcc/config/i386/constraints.md +++ b/gcc/config/i386/constraints.md @@ -348,6 +348,10 @@ (define_constraint "Wf" to double word size." (match_operand 0 "x86_64_dwzext_immediate_operand")) +(define_constraint "Ws" + "A symbolic reference or label reference." + (match_code "const,symbol_ref,label_ref")) + (define_constraint "Z" "32-bit unsigned integer constant, or a symbolic reference known to fit that range (for immediate operands in zero-extending x86-64 diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi index 47a87d6ceec..b0c61925120 100644 --- a/gcc/doc/md.texi +++ b/gcc/doc/md.texi @@ -4275,6 +4275,10 @@ require non-@code{VOIDmode} immediate operands). 128-bit integer constant where both the high and low 64-bit word satisfy the @code{e} constraint. +@item Ws +A symbolic reference or label reference. +You can use the @code{%p} modifier to print the raw symbol. + @item Z 32-bit unsigned integer constant, or a symbolic reference known to fit that range (for immediate operands in zero-extending x86-64 diff --git a/gcc/testsuite/gcc.target/i386/asm-raw-symbol.c b/gcc/testsuite/gcc.target/i386/asm-raw-symbol.c new file mode 100644 index 00000000000..b7854567dd9 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/asm-raw-symbol.c @@ -0,0 +1,13 @@ +/* { dg-do compile } */ + +extern int var; + +void +func (void) +{ + __asm__ ("@ %p0" : : "Ws" (func)); + __asm__ ("@ %p0" : : "Ws" (&var + 1)); +} + +/* { dg-final { scan-assembler "@ func" } } */ +/* { dg-final { scan-assembler "@ var\\+4" } } */ -- 2.43.0.275.g3460e3d667-goog