Hi,
The patch corrects the definition of
TARGET_EFFICIENT_OVERLAPPING_UNALIGNED and change its name to a
comprehensible name.
Bootstrapped and tested on x86 and powerpc64-linux BE and LE with no
regressions. Is this OK for trunk?
Thanks
Gui Haochen
ChangeLog
rs6000: Correct definition of macro of fixed point efficient unaligned
Marco TARGET_EFFICIENT_OVERLAPPING_UNALIGNED is used in rs6000-string.cc to
guard whether a platform is efficient on fixed point unaligned load/store.
It's originally defined by TARGET_EFFICIENT_UNALIGNED_VSX which is enabled
from P8 and can be disabled by mno-vsx option. So the definition is wrong.
This patch corrects the problem and define it by "!STRICT_ALIGNMENT" which
is true on P7 BE and P8 above.
gcc/
* config/rs6000/rs6000.h (TARGET_EFFICIENT_OVERLAPPING_UNALIGNED):
Rename to...
(TARGET_EFFICIENT_UNALIGNED_FIXEDPOINT): ...this, set it to
!STRICT_ALIGNMENT.
* config/rs6000/rs6000-string.cc (select_block_compare_mode):
Replace TARGET_EFFICIENT_OVERLAPPING_UNALIGNED with
TARGET_EFFICIENT_UNALIGNED_FIXEDPOINT.
(select_block_compare_mode): Likewise.
(expand_block_compare_gpr): Likewise.
(expand_block_compare): Likewise.
(expand_strncmp_gpr_sequence): Likewise.
gcc/testsuite/
* gcc.target/powerpc/target_efficient_unaligned_fixedpoint-1.c: New.
* gcc.target/powerpc/target_efficient_unaligned_fixedpoint-2.c: New.
patch.diff
diff --git a/gcc/config/rs6000/rs6000-string.cc
b/gcc/config/rs6000/rs6000-string.cc
index 44a946cd453..d4030854b2a 100644
--- a/gcc/config/rs6000/rs6000-string.cc
+++ b/gcc/config/rs6000/rs6000-string.cc
@@ -305,7 +305,7 @@ select_block_compare_mode (unsigned HOST_WIDE_INT offset,
else if (bytes == GET_MODE_SIZE (QImode))
return QImode;
else if (bytes < GET_MODE_SIZE (SImode)
- && TARGET_EFFICIENT_OVERLAPPING_UNALIGNED
+ && TARGET_EFFICIENT_UNALIGNED_FIXEDPOINT
&& offset >= GET_MODE_SIZE (SImode) - bytes)
/* This matches the case were we have SImode and 3 bytes
and offset >= 1 and permits us to move back one and overlap
@@ -313,7 +313,7 @@ select_block_compare_mode (unsigned HOST_WIDE_INT offset,
unwanted bytes off of the input. */
return SImode;
else if (word_mode_ok && bytes < UNITS_PER_WORD
- && TARGET_EFFICIENT_OVERLAPPING_UNALIGNED
+ && TARGET_EFFICIENT_UNALIGNED_FIXEDPOINT
&& offset >= UNITS_PER_WORD-bytes)
/* Similarly, if we can use DImode it will get matched here and
can do an overlapping read that ends at the end of the block. */
@@ -1749,7 +1749,7 @@ expand_block_compare_gpr(unsigned HOST_WIDE_INT bytes,
unsigned int base_align,
load_mode_size = GET_MODE_SIZE (load_mode);
if (bytes >= load_mode_size)
cmp_bytes = load_mode_size;
- else if (TARGET_EFFICIENT_OVERLAPPING_UNALIGNED)
+ else if (TARGET_EFFICIENT_UNALIGNED_FIXEDPOINT)
{
/* Move this load back so it doesn't go past the end.
P8/P9 can do this efficiently. */
@@ -2026,7 +2026,7 @@ expand_block_compare (rtx operands[])
/* The code generated for p7 and older is not faster than glibc
memcmp if alignment is small and length is not short, so bail
out to avoid those conditions. */
- if (!TARGET_EFFICIENT_OVERLAPPING_UNALIGNED
+ if (!TARGET_EFFICIENT_UNALIGNED_FIXEDPOINT
&& ((base_align == 1 && bytes > 16)
|| (base_align == 2 && bytes > 32)))
return false;
@@ -2168,7 +2168,7 @@ expand_strncmp_gpr_sequence (unsigned HOST_WIDE_INT
bytes_to_compare,
load_mode_size = GET_MODE_SIZE (load_mode);
if (bytes_to_compare >= load_mode_size)
cmp_bytes = load_mode_size;
- else if (TARGET_EFFICIENT_OVERLAPPING_UNALIGNED)
+ else if (TARGET_EFFICIENT_UNALIGNED_FIXEDPOINT)
{
/* Move this load back so it doesn't go past the end.
P8/P9 can do this efficiently. */
diff --git a/gcc/config/rs6000/rs6000.h b/gcc/config/rs6000/rs6000.h
index 326c45221e9..2f3a82942c1 100644
--- a/gcc/config/rs6000/rs6000.h
+++ b/gcc/config/rs6000/rs6000.h
@@ -483,9 +483,9 @@ extern int rs6000_vector_align[];
#define TARGET_NO_SF_SUBREG TARGET_DIRECT_MOVE_64BIT
#define TARGET_ALLOW_SF_SUBREG (!TARGET_DIRECT_MOVE_64BIT)
-/* This wants to be set for p8 and newer. On p7, overlapping unaligned
- loads are slow. */
-#define TARGET_EFFICIENT_OVERLAPPING_UNALIGNED TARGET_EFFICIENT_UNALIGNED_VSX
+/* Like TARGET_EFFICIENT_UNALIGNED_VSX, indicates if unaligned fixed point
+ loads/stores are efficient. */
+#define TARGET_EFFICIENT_UNALIGNED_FIXEDPOINT (!STRICT_ALIGNMENT)
/* Byte/char syncs were added as phased in for ISA 2.06B, but are not present
in power7, so conditionalize them on p8 features. TImode syncs need quad
diff --git
a/gcc/testsuite/gcc.target/powerpc/target_efficient_unaligned_fixedpoint-1.c
b/gcc/testsuite/gcc.target/powerpc/target_efficient_unaligned_fixedpoint-1.c
new file mode 100644
index 00000000000..e090755e23f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/target_efficient_unaligned_fixedpoint-1.c
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mdejagnu-cpu=power8 -mno-vsx" } */
+/* { dg-final { scan-assembler-not {\mbl memcmp\M} } } */
+
+int foo (const char* s1, const char* s2)
+{
+ return __builtin_memcmp (s1, s2, 20);
+}
diff --git
a/gcc/testsuite/gcc.target/powerpc/target_efficient_unaligned_fixedpoint-2.c
b/gcc/testsuite/gcc.target/powerpc/target_efficient_unaligned_fixedpoint-2.c
new file mode 100644
index 00000000000..c7ebcd90a0b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/target_efficient_unaligned_fixedpoint-2.c
@@ -0,0 +1,8 @@
+/* { dg-do compile { target le } } */
+/* { dg-options "-O2 -mdejagnu-cpu=power7 -mno-vsx" } */
+/* { dg-final { scan-assembler-times {\mbl memcmp\M} 1 } } */
+
+int foo (const char* s1, const char* s2)
+{
+ return __builtin_memcmp (s1, s2, 20);
+}
