[gcc r14-2205] mips: Fix overaligned function arguments [PR109435]

[gcc r14-2205] mips: Fix overaligned function arguments [PR109435]

[YunQiang Su]

https://gcc.gnu.org/g:e20abdb749d0c0c8552da998ff8ec139b830f5eb

commit r14-2205-ge20abdb749d0c0c8552da998ff8ec139b830f5eb
Author: Jovan Dmitrovic <Jovan.Dmitrovic@Syrmia.com>
Date:   Mon Jun 26 17:00:20 2023 +0200

    mips: Fix overaligned function arguments [PR109435]
    
    This patch changes alignment for typedef types when passed as
    arguments, making the alignment equal to the alignment of
    original (aliased) types.
    
    This change makes it impossible for a typedef type to have
    alignment that is less than its size.
    
    2023-06-27  Jovan Dmitrović  <jovan.dmitrovic@syrmia.com>
    
    gcc/ChangeLog:
    
            PR target/109435
            * config/mips/mips.cc (mips_function_arg_alignment): Returns
            the alignment of function argument. In case of typedef type,
            it returns the aligment of the aliased type.
            (mips_function_arg_boundary): Relocated calculation of the
            aligment of function arguments.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.target/mips/align-1-n64.c: New test.
            * gcc.target/mips/align-1-o32.c: New test.

Diff:
---
 gcc/config/mips/mips.cc                     | 19 ++++++++++++++++++-
 gcc/testsuite/gcc.target/mips/align-1-n64.c | 20 ++++++++++++++++++++
 gcc/testsuite/gcc.target/mips/align-1-o32.c | 20 ++++++++++++++++++++
 3 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/gcc/config/mips/mips.cc b/gcc/config/mips/mips.cc
index 999127a72e7..1b9880d5cf5 100644
--- a/gcc/config/mips/mips.cc
+++ b/gcc/config/mips/mips.cc
@@ -6271,6 +6271,23 @@ mips_arg_partial_bytes (cumulative_args_t cum, const function_arg_info &arg)
   return info.stack_words > 0 ? info.reg_words * UNITS_PER_WORD : 0;
 }
 
+/* Given MODE and TYPE of a function argument, return the alignment in
+   bits.
+   In case of typedef, alignment of its original type is
+   used.  */
+
+static unsigned int
+mips_function_arg_alignment (machine_mode mode, const_tree type)
+{
+  if (!type)
+    return GET_MODE_ALIGNMENT (mode);
+
+  if (is_typedef_decl (TYPE_NAME (type)))
+    type = DECL_ORIGINAL_TYPE (TYPE_NAME (type));
+
+  return TYPE_ALIGN (type);
+}
+
 /* Implement TARGET_FUNCTION_ARG_BOUNDARY.  Every parameter gets at
    least PARM_BOUNDARY bits of alignment, but will be given anything up
    to STACK_BOUNDARY bits if the type requires it.  */
@@ -6279,8 +6296,8 @@ static unsigned int
 mips_function_arg_boundary (machine_mode mode, const_tree type)
 {
   unsigned int alignment;
+  alignment = mips_function_arg_alignment (mode, type);
 
-  alignment = type ? TYPE_ALIGN (type) : GET_MODE_ALIGNMENT (mode);
   if (alignment < PARM_BOUNDARY)
     alignment = PARM_BOUNDARY;
   if (alignment > STACK_BOUNDARY)
diff --git a/gcc/testsuite/gcc.target/mips/align-1-n64.c b/gcc/testsuite/gcc.target/mips/align-1-n64.c
new file mode 100644
index 00000000000..3ede539c3a4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/mips/align-1-n64.c
@@ -0,0 +1,20 @@
+/* Check that typedef alignment does not affect passing of function
+   parameters for N64/N32 ABIs.  */
+/* { dg-do compile { target { "mips*-*-*" } } } */
+/* { dg-options "-mabi=64"  } */
+/* { dg-skip-if "" { *-*-* } { "-flto" } { "" } } */
+
+typedef struct ui8
+{
+  unsigned v[8];
+} uint8 __attribute__ ((aligned(64)));
+
+unsigned
+callee (int x, uint8 a)
+{
+  return a.v[0];
+}
+
+/* { dg-final { scan-assembler "\tsd\t\\\$5,0\\(\\\$\[0-9\]\\)" } } */
+/* { dg-final { scan-assembler "\tsd\t\\\$6,8\\(\\\$\[0-9\]\\)" } } */
+/* { dg-final { scan-assembler "\tsd\t\\\$7,16\\(\\\$\[0-9\]\\)" } } */
diff --git a/gcc/testsuite/gcc.target/mips/align-1-o32.c b/gcc/testsuite/gcc.target/mips/align-1-o32.c
new file mode 100644
index 00000000000..e043d6a3eca
--- /dev/null
+++ b/gcc/testsuite/gcc.target/mips/align-1-o32.c
@@ -0,0 +1,20 @@
+/* Check that typedef alignment does not affect passing of function
+   parameters for O32 ABI.  */
+/* { dg-do compile { target { "mips*-*-*" } } } */
+/* { dg-options "-mabi=32"  } */
+/* { dg-skip-if "" { *-*-* } { "-flto" } { "" } } */
+
+typedef struct ui8
+{
+  unsigned v[8];
+} uint8 __attribute__ ((aligned(64)));
+
+unsigned
+callee (int x, uint8 a)
+{
+  return a.v[0];
+}
+
+/* { dg-final { scan-assembler "\tsw\t\\\$5,1\\d\\d\\(\\\$(sp|fp)\\)" } } */
+/* { dg-final { scan-assembler "\tsw\t\\\$6,1\\d\\d\\(\\\$(sp|fp)\\)" } } */
+/* { dg-final { scan-assembler "\tsw\t\\\$7,1\\d\\d\\(\\\$(sp|fp)\\)" } } */