summaryrefslogtreecommitdiff
path: root/gcc/gcc-3.3.3/arm-ldm.dpatch
diff options
context:
space:
mode:
Diffstat (limited to 'gcc/gcc-3.3.3/arm-ldm.dpatch')
-rw-r--r--gcc/gcc-3.3.3/arm-ldm.dpatch148
1 files changed, 148 insertions, 0 deletions
diff --git a/gcc/gcc-3.3.3/arm-ldm.dpatch b/gcc/gcc-3.3.3/arm-ldm.dpatch
index e69de29bb2..561624f39c 100644
--- a/gcc/gcc-3.3.3/arm-ldm.dpatch
+++ b/gcc/gcc-3.3.3/arm-ldm.dpatch
@@ -0,0 +1,148 @@
+#! /bin/sh -e
+
+src=gcc
+if [ $# -eq 3 -a "$2" = '-d' ]; then
+ pdir="-d $3"
+ src=$3/gcc
+elif [ $# -ne 1 ]; then
+ echo >&2 "`basename $0`: script expects -patch|-unpatch as argument"
+ exit 1
+fi
+case "$1" in
+ -patch)
+ patch $pdir -f --no-backup-if-mismatch -p0 --fuzz 10 < $0
+ ;;
+ -unpatch)
+ patch $pdir -f --no-backup-if-mismatch -R -p0 --fuzz 10 < $0
+ ;;
+ *)
+ echo >&2 "`basename $0`: script expects -patch|-unpatch as argument"
+ exit 1
+esac
+exit 0
+
+# DP: try harder to avoid ldm in function epilogues
+
+--- gcc/config/arm/arm.c Fri Mar 5 18:49:42 2004
++++ gcc/config/arm/arm.c Fri Mar 5 16:00:21 2004
+@@ -7598,6 +7629,26 @@
+ return_used_this_function = 0;
+ }
+
++/* Return the number (counting from 0) of
++ the least significant set bit in MASK. */
++
++#ifdef __GNUC__
++inline
++#endif
++static int
++number_of_first_bit_set (mask)
++ int mask;
++{
++ int bit;
++
++ for (bit = 0;
++ (mask & (1 << bit)) == 0;
++ ++bit)
++ continue;
++
++ return bit;
++}
++
+ const char *
+ arm_output_epilogue (really_return)
+ int really_return;
+@@ -7788,27 +7839,47 @@
+ saved_regs_mask |= (1 << PC_REGNUM);
+ }
+
+- /* Load the registers off the stack. If we only have one register
+- to load use the LDR instruction - it is faster. */
+- if (saved_regs_mask == (1 << LR_REGNUM))
+- {
+- /* The exception handler ignores the LR, so we do
+- not really need to load it off the stack. */
+- if (eh_ofs)
+- asm_fprintf (f, "\tadd\t%r, %r, #4\n", SP_REGNUM, SP_REGNUM);
+- else
+- asm_fprintf (f, "\tldr\t%r, [%r], #4\n", LR_REGNUM, SP_REGNUM);
+- }
+- else if (saved_regs_mask)
++ if (saved_regs_mask)
+ {
+- if (saved_regs_mask & (1 << SP_REGNUM))
+- /* Note - write back to the stack register is not enabled
+- (ie "ldmfd sp!..."). We know that the stack pointer is
+- in the list of registers and if we add writeback the
+- instruction becomes UNPREDICTABLE. */
+- print_multi_reg (f, "ldmfd\t%r", SP_REGNUM, saved_regs_mask);
++ /* Load the registers off the stack. If we only have one register
++ to load use the LDR instruction - it is faster. */
++ if (bit_count (saved_regs_mask) == 1)
++ {
++ int reg = number_of_first_bit_set (saved_regs_mask);
++
++ switch (reg)
++ {
++ case SP_REGNUM:
++ /* Mustn't use base writeback when loading SP. */
++ asm_fprintf (f, "\tldr\t%r, [%r]\n", SP_REGNUM, SP_REGNUM);
++ break;
++
++ case LR_REGNUM:
++ if (eh_ofs)
++ {
++ /* The exception handler ignores the LR, so we do
++ not really need to load it off the stack. */
++ asm_fprintf (f, "\tadd\t%r, %r, #4\n", SP_REGNUM, SP_REGNUM);
++ break;
++ }
++ /* else fall through */
++
++ default:
++ asm_fprintf (f, "\tldr\t%r, [%r], #4\n", reg, SP_REGNUM);
++ break;
++ }
++ }
+ else
+- print_multi_reg (f, "ldmfd\t%r!", SP_REGNUM, saved_regs_mask);
++ {
++ if (saved_regs_mask & (1 << SP_REGNUM))
++ /* Note - write back to the stack register is not enabled
++ (ie "ldmfd sp!..."). We know that the stack pointer is
++ in the list of registers and if we add writeback the
++ instruction becomes UNPREDICTABLE. */
++ print_multi_reg (f, "ldmfd\t%r", SP_REGNUM, saved_regs_mask);
++ else
++ print_multi_reg (f, "ldmfd\t%r!", SP_REGNUM, saved_regs_mask);
++ }
+ }
+
+ if (current_function_pretend_args_size)
+@@ -9610,26 +9677,6 @@
+ }
+ }
+
+-/* Return the number (counting from 0) of
+- the least significant set bit in MASK. */
+-
+-#ifdef __GNUC__
+-inline
+-#endif
+-static int
+-number_of_first_bit_set (mask)
+- int mask;
+-{
+- int bit;
+-
+- for (bit = 0;
+- (mask & (1 << bit)) == 0;
+- ++bit)
+- continue;
+-
+- return bit;
+-}
+-
+ /* Generate code to return from a thumb function.
+ If 'reg_containing_return_addr' is -1, then the return address is
+ actually on the stack, at the stack pointer. */