From 464c1720419b8021f87e11ee3bbf8d1aebd1eb62 Mon Sep 17 00:00:00 2001
From: Petar Jovanovic <mips32r2@gmail.com>
Date: Fri, 4 Nov 2016 18:21:22 +0000
Subject: [PATCH] mips: Add redir for index function in ld.so.1

Redirect index function in ld.so.1.
Optimize the existing strlen function implementations.
This removes warnings coming from optimized index and strlen functions
in ld.so.1.

Patch by Aleksandar Rikalo.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@16117
---
 coregrind/m_redir.c             | 14 +++++-
 coregrind/m_trampoline.S        | 88 ++++++++++++++++++++++-----------
 coregrind/pub_core_trampoline.h |  2 +
 3 files changed, 74 insertions(+), 30 deletions(-)

diff --git a/coregrind/m_redir.c b/coregrind/m_redir.c
index ff35009a7c..76fc6749e0 100644
--- a/coregrind/m_redir.c
+++ b/coregrind/m_redir.c
@@ -1567,10 +1567,15 @@ void VG_(redir_initialise) ( void )
 
       /* this is mandatory - can't sanely continue without it */
       add_hardwired_spec(
-         "ld.so.3", "strlen",
+         "ld.so.1", "strlen",
          (Addr)&VG_(mips32_linux_REDIR_FOR_strlen),
          complain_about_stripped_glibc_ldso
       );
+      add_hardwired_spec(
+         "ld.so.1", "index",
+         (Addr)&VG_(mips32_linux_REDIR_FOR_index),
+         complain_about_stripped_glibc_ldso
+      );
    }
 
 #  elif defined(VGP_mips64_linux)
@@ -1578,10 +1583,15 @@ void VG_(redir_initialise) ( void )
 
       /* this is mandatory - can't sanely continue without it */
       add_hardwired_spec(
-         "ld.so.3", "strlen",
+         "ld.so.1", "strlen",
          (Addr)&VG_(mips64_linux_REDIR_FOR_strlen),
          complain_about_stripped_glibc_ldso
       );
+      add_hardwired_spec(
+         "ld.so.1", "index",
+         (Addr)&VG_(mips64_linux_REDIR_FOR_index),
+         complain_about_stripped_glibc_ldso
+      );
    }
 
 #  elif defined(VGP_tilegx_linux)
diff --git a/coregrind/m_trampoline.S b/coregrind/m_trampoline.S
index ef7c4e69b3..da163a3806 100644
--- a/coregrind/m_trampoline.S
+++ b/coregrind/m_trampoline.S
@@ -1269,24 +1269,43 @@ VG_(mips32_linux_SUBST_FOR_rt_sigreturn):
 	
 /* There's no particular reason that this needs to be handwritten
    assembly, but since that's what this file contains, here's a
-   simple strlen implementation (written in C and compiled by gcc.)
+   simple index() and strlen() implementations.
 */
+
+.set push
+.set noreorder
+
+.global VG_(mips32_linux_REDIR_FOR_index)
+.type   VG_(mips32_linux_REDIR_FOR_index), @function
+VG_(mips32_linux_REDIR_FOR_index):
+      move $v0, $a0
+   index_loop:
+      lbu $t0, 0($v0)
+      beq $t0, $a1, index_end
+      nop
+      bne $t0, $zero, index_loop
+      addiu $v0, $v0, 1
+      move $v0, $zero
+   index_end:
+      jr $ra
+      nop
+.size VG_(mips32_linux_REDIR_FOR_index), .-VG_(mips32_linux_REDIR_FOR_index)
+
 .global VG_(mips32_linux_REDIR_FOR_strlen)
 .type   VG_(mips32_linux_REDIR_FOR_strlen), @function
 VG_(mips32_linux_REDIR_FOR_strlen):
-      li $v0, 0
-      //la $a0, string
-      j strlen_cond
+      move $v0, $a0
    strlen_loop:
-      addiu $v0, $v0, 1
-      addiu $a0, $a0, 1
-   strlen_cond:
-      lbu $t0, ($a0)
+      lbu $t0, 0($a0)
       bne $t0, $zero, strlen_loop
-    jr $ra
-
+      addiu $a0, $a0, 1
+      subu $v0, $a0, $v0
+      jr $ra
+      addiu $v0, $v0, -1
 .size VG_(mips32_linux_REDIR_FOR_strlen), .-VG_(mips32_linux_REDIR_FOR_strlen)
 
+.set pop
+
 .global VG_(trampoline_stuff_end)
 VG_(trampoline_stuff_end):
 
@@ -1319,30 +1338,43 @@ VG_(mips64_linux_SUBST_FOR_rt_sigreturn):
 
 /* There's no particular reason that this needs to be handwritten
    assembly, but since that's what this file contains, here's a
-   simple strlen implementation (written in C and compiled by gcc.)
+   simple index() and strlen() implementations.
 */
+
+.set push
+.set noreorder
+
+.global VG_(mips64_linux_REDIR_FOR_index)
+.type   VG_(mips64_linux_REDIR_FOR_index), @function
+VG_(mips64_linux_REDIR_FOR_index):
+      move $v0, $a0
+   index_loop:
+      lbu $t0, 0($v0)
+      beq $t0, $a1, index_end
+      nop
+      bne $t0, $zero, index_loop
+      daddiu $v0, $v0, 1
+      move $v0, $zero
+   index_end:
+      jr $ra
+      nop
+.size VG_(mips64_linux_REDIR_FOR_index), .-VG_(mips64_linux_REDIR_FOR_index)
+
 .global VG_(mips64_linux_REDIR_FOR_strlen)
 .type   VG_(mips64_linux_REDIR_FOR_strlen), @function
 VG_(mips64_linux_REDIR_FOR_strlen):
-        lbu $12, 0($4)
-        li  $13, 0
-        beq $12, $0, M01 
-        nop
-
-M02: 
-        addiu $13, $13, 1 
-        addiu $4, $4, 1 
-        lbu $12, 0($4) 
-        bne $12, $0, M02 
-        nop 
-
-M01: 
-        move $2, $13 
-        jr $31 
-        nop
-
+      move $v0, $a0
+   strlen_loop:
+      lbu $t0, 0($a0)
+      bne $t0, $zero, strlen_loop
+      daddiu $a0, $a0, 1
+      dsubu $v0, $a0, $v0
+      jr $ra
+      daddiu $v0, $v0, -1
 .size VG_(mips64_linux_REDIR_FOR_strlen), .-VG_(mips64_linux_REDIR_FOR_strlen)
 
+.set pop
+
 .global VG_(trampoline_stuff_end)
 VG_(trampoline_stuff_end):
 
diff --git a/coregrind/pub_core_trampoline.h b/coregrind/pub_core_trampoline.h
index 1396519e89..3f5516d439 100644
--- a/coregrind/pub_core_trampoline.h
+++ b/coregrind/pub_core_trampoline.h
@@ -154,11 +154,13 @@ extern void* VG_(s390x_linux_REDIR_FOR_index) ( void*, Long );
 #if defined(VGP_mips32_linux)
 extern Addr  VG_(mips32_linux_SUBST_FOR_sigreturn);
 extern Addr  VG_(mips32_linux_SUBST_FOR_rt_sigreturn);
+extern Char* VG_(mips32_linux_REDIR_FOR_index)( const Char*, Int );
 extern UInt  VG_(mips32_linux_REDIR_FOR_strlen)( void* );
 #endif
 
 #if defined(VGP_mips64_linux)
 extern Addr  VG_(mips64_linux_SUBST_FOR_rt_sigreturn);
+extern Char* VG_(mips64_linux_REDIR_FOR_index)( const Char*, Int );
 extern UInt  VG_(mips64_linux_REDIR_FOR_strlen)( void* );
 #endif
 
-- 
2.47.2