Hi,
This change removes an extraneous NOP instruction placed at the end of
code produced by each of byte-swap patterns due to the expansion of the
(const_int 0) RTL unnecessarily produced by `define_split' definitions.
Updated patterns follow what other targets do in corresponding situations.
The change in output produced can be illustrated with the following
simple example:
$ cat bswap.c
long long
bswap (long long i)
{
return __builtin_bswap64 (i);
}
$ powerpc-linux-gnu-gcc -S -dp -o bswap.s bswap.c
This currently produces the following code:
.file "bswap.c"
.section ".text"
.align 2
.globl bswap
.type bswap, @function
bswap:
stwu 1,-32(1) # 20 movsi_update/2 [length = 4]
stw 31,28(1) # 21 *movsi_internal1/4 [length = 4]
mr 31,1 # 22 *movsi_internal1/1 [length = 4]
stw 3,8(31) # 31 *movsi_internal1/4 [length = 4]
stw 4,12(31) # 32 *movsi_internal1/4 [length = 4]
lwz 9,8(31) # 33 *movsi_internal1/3 [length = 4]
lwz 10,12(31) # 34 *movsi_internal1/3 [length = 4]
rlwinm 7,10,8,0xffffffff # 38 rotlsi3/2 [length = 4]
rlwimi 7,10,24,0,7 # 39 insvsi_internal [length = 4]
rlwimi 7,10,24,16,23 # 40 *insvsi_internal1 [length = 4]
rlwinm 8,9,8,0xffffffff # 41 rotlsi3/2 [length = 4]
rlwimi 8,9,24,0,7 # 42 insvsi_internal [length = 4]
rlwimi 8,9,24,16,23 # 43 *insvsi_internal1 [length = 4]
nop # 37 nop [length = 4]
mr 10,8 # 44 *movsi_internal1/1 [length = 4]
mr 9,7 # 45 *movsi_internal1/1 [length = 4]
mr 3,9 # 46 *movsi_internal1/1 [length = 4]
mr 4,10 # 47 *movsi_internal1/1 [length = 4]
addi 11,31,32 # 25 *addsi3_internal1/2 [length = 4]
lwz 31,-4(11) # 26 *movsi_internal1/3 [length = 4]
mr 1,11 # 28 *movsi_internal1/1 [length = 4]
blr # 29 *return_internal_si [length = 4]
.size bswap,.-bswap
Notice the NOP in the middle. With this change applied this code is
produced instead:
.file "bswap.c"
.section ".text"
.align 2
.globl bswap
.type bswap, @function
bswap:
stwu 1,-32(1) # 20 movsi_update/2 [length = 4]
stw 31,28(1) # 21 *movsi_internal1/4 [length = 4]
mr 31,1 # 22 *movsi_internal1/1 [length = 4]
stw 3,8(31) # 31 *movsi_internal1/4 [length = 4]
stw 4,12(31) # 32 *movsi_internal1/4 [length = 4]
lwz 9,8(31) # 33 *movsi_internal1/3 [length = 4]
lwz 10,12(31) # 34 *movsi_internal1/3 [length = 4]
rlwinm 7,10,8,0xffffffff # 37 rotlsi3/2 [length = 4]
rlwimi 7,10,24,0,7 # 38 insvsi_internal [length = 4]
rlwimi 7,10,24,16,23 # 39 *insvsi_internal1 [length = 4]
rlwinm 8,9,8,0xffffffff # 40 rotlsi3/2 [length = 4]
rlwimi 8,9,24,0,7 # 41 insvsi_internal [length = 4]
rlwimi 8,9,24,16,23 # 42 *insvsi_internal1 [length = 4]
mr 10,8 # 43 *movsi_internal1/1 [length = 4]
mr 9,7 # 44 *movsi_internal1/1 [length = 4]
mr 3,9 # 45 *movsi_internal1/1 [length = 4]
mr 4,10 # 46 *movsi_internal1/1 [length = 4]
addi 11,31,32 # 25 *addsi3_internal1/2 [length = 4]
lwz 31,-4(11) # 26 *movsi_internal1/3 [length = 4]
mr 1,11 # 28 *movsi_internal1/1 [length = 4]
blr # 29 *return_internal_si [length = 4]
.size bswap,.-bswap
This has been regression tested with the powerpc-eabi target and the
following multilibs:
-mcpu=603e
-mcpu=603e -msoft-float
-mcpu=8540 -mfloat-gprs=single -mspe=yes -mabi=spe
-mcpu=8540 -mfloat-gprs=single -mspe=yes -mabi=spe -msoft-float
-mcpu=8548 -mfloat-gprs=double -mspe=yes -mabi=spe
-mcpu=8548 -mfloat-gprs=double -mspe=yes -mabi=spe -mlittle
-mcpu=8548 -mfloat-gprs=double -mspe=yes -mabi=spe -msoft-float
-mcpu=7400 -maltivec -mabi=altivec
as well as the powerpc-linux-gnu target and the following multilibs:
-mcpu=603e
-mcpu=603e -msoft-float
-mcpu=8540 -mfloat-gprs=single -mspe=yes -mabi=spe
-mcpu=8548 -mfloat-gprs=double -mspe=yes -mabi=spe
-mcpu=7400 -maltivec -mabi=altivec
-mcpu=e5500 -m64
OK to apply?
2014-06-20 Maciej W. Rozycki <ma...@codesourcery.com>
gcc/
* config/rs6000/rs6000.md: Append `DONE' to preparation
statements of `bswap' pattern splitters.
Maciej
gcc-ppc-bswap-done.diff
Index: gcc-fsf-trunk-quilt/gcc/config/rs6000/rs6000.md
===================================================================
--- gcc-fsf-trunk-quilt.orig/gcc/config/rs6000/rs6000.md 2014-06-10
21:46:36.000000000 +0100
+++ gcc-fsf-trunk-quilt/gcc/config/rs6000/rs6000.md 2014-06-11
02:40:42.028572744 +0100
@@ -2475,6 +2475,7 @@
emit_insn (gen_bswapsi2 (op4_32, word_high));
emit_insn (gen_ashldi3 (dest, op3, GEN_INT (32)));
emit_insn (gen_iordi3 (dest, dest, op4));
+ DONE;
}")
(define_split
@@ -2536,6 +2537,7 @@
}
emit_insn (gen_bswapsi2 (word_high, src_si));
emit_insn (gen_bswapsi2 (word_low, op3_si));
+ DONE;
}")
(define_split
@@ -2563,6 +2565,7 @@
emit_insn (gen_bswapsi2 (op3_si, op2_si));
emit_insn (gen_ashldi3 (dest, dest, GEN_INT (32)));
emit_insn (gen_iordi3 (dest, dest, op3));
+ DONE;
}")
(define_insn "bswapdi2_32bit"
@@ -2619,6 +2622,7 @@
emit_insn (gen_bswapsi2 (dest2, word1));
emit_insn (gen_bswapsi2 (dest1, word2));
+ DONE;
}")
(define_split
@@ -2667,6 +2671,7 @@
emit_insn (gen_bswapsi2 (word2, src1));
emit_insn (gen_bswapsi2 (word1, src2));
+ DONE;
}")
(define_split
@@ -2686,6 +2691,7 @@
emit_insn (gen_bswapsi2 (dest1, src2));
emit_insn (gen_bswapsi2 (dest2, src1));
+ DONE;
}")
(define_insn "mulsi3"
