> So how about keeping:
>
> rtx y = simplify_gen_vec_select (SET_DEST (x), i);
>
> but skipping the following code if "y" itself is a REG?
Yes, sounds reasonable, attached is v3 which does that.
Bootstrapped and regtested on x86, aarch64, and power10.
Regtested on riscv64.
Regards
Robin
[PATCH v3] cse: Only use non-reg vec_select simplifications. [PR121649]
When merging classes, cse computes new equivalences for constants.
In the PR we have
(insn 1173 1172 1174 2 (set (reg:V8QI 33 v1)
(const_vector:V8QI [
(const_int 3 [0x3])
(const_int -4 [0xfffffffffffffffc])
(const_int 0 [0]) repeated x6
])) "pr121649.c":63:3 1325 {*aarch64_simd_movv8qi}
(nil))
of which the second element is selected:
(insn 1178 1177 1179 2 (set (reg:QI 4 x4)
(vec_select:QI (reg:V8QI 33 v1)
(parallel [
(const_int 1 [0x1])
]))) "pr121649.c":63:3 2968 {aarch64_get_lanev8qi}
(expr_list:REG_EQUAL (const_int -4 [0xfffffffffffffffc])
(nil)))
We find (const_int 3 [0x3]) and a few others to be equivalent, among
them (reg:QI v1). This is a "fake set" that we create to help CSE extract
const_vector elements and reuse them. Element 0 is special, though. We
lowpart-subreg simplify it to (reg:QI v1) directly and, as the register stays
the same, consider it equivalent to (reg:V8QI v1).
Because both equivs refer to the same hard reg, in merge_equiv_classes, the
old (reg:V8QI) equiv is deleted and replaced by the new (reg:QI) one,
forgetting that the old equiv had 7 more elements.
Subsequently, extracting element 1 of a zero-extended QImode register results
in "0" instead of the correct "-4".
Therefore, this patch only uses those vec_select simplification that do
not directly result in a register.
PR rtl-optimization/121649
gcc/ChangeLog:
* cse.cc (find_sets_in_insn): Only use non-reg vec_select
simplifications.
gcc/testsuite/ChangeLog:
* gcc.dg/torture/pr121649.c: New test.
---
gcc/cse.cc | 7 +-
gcc/testsuite/gcc.dg/torture/pr121649.c | 130 ++++++++++++++++++++++++
2 files changed, 135 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/torture/pr121649.c
diff --git a/gcc/cse.cc b/gcc/cse.cc
index 4eaef602366..e5fa88f9de5 100644
--- a/gcc/cse.cc
+++ b/gcc/cse.cc
@@ -4298,8 +4298,11 @@ find_sets_in_insn (rtx_insn *insn, vec<struct set>
*psets)
used to tell CSE how to get to a particular constant. */
rtx y = simplify_gen_vec_select (SET_DEST (x), i);
gcc_assert (y);
- rtx set = gen_rtx_SET (y, CONST_VECTOR_ELT (src, i));
- add_to_set (psets, set, true);
+ if (!REG_P (y))
+ {
+ rtx set = gen_rtx_SET (y, CONST_VECTOR_ELT (src, i));
+ add_to_set (psets, set, true);
+ }
}
}
else
diff --git a/gcc/testsuite/gcc.dg/torture/pr121649.c
b/gcc/testsuite/gcc.dg/torture/pr121649.c
new file mode 100644
index 00000000000..8af7e9b60fe
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr121649.c
@@ -0,0 +1,130 @@
+/* { dg-do run { target bitint } } */
+/* { dg-additional-options "-Wno-psabi" } */
+
+typedef __attribute__((__vector_size__ (8))) char v64s8;
+typedef __attribute__((__vector_size__ (8))) short v64s16;
+typedef __attribute__((__vector_size__ (8))) int v64s32;
+typedef __attribute__((__vector_size__ (16))) char v128s8;
+typedef __attribute__((__vector_size__ (16))) short v128s16;
+typedef __attribute__((__vector_size__ (16))) int v128s32;
+typedef __attribute__((__vector_size__ (16))) long v128s64;
+typedef __attribute__((__vector_size__ (32))) char v256s8;
+typedef __attribute__((__vector_size__ (32))) short v256s16;
+typedef __attribute__((__vector_size__ (32))) int v256s32;
+typedef __attribute__((__vector_size__ (32))) long v256s64;
+typedef __attribute__((__vector_size__ (32))) __int128 v256s128;
+typedef __attribute__((__vector_size__ (64))) char v512s8;
+typedef __attribute__((__vector_size__ (64))) short v512s16;
+typedef __attribute__((__vector_size__ (64))) int v512s32;
+typedef __attribute__((__vector_size__ (64))) long v512s64;
+typedef __attribute__((__vector_size__ (64))) __int128 v512s128;
+
+__attribute__((__noipa__)) __attribute__((__cold__)) void
+foo0 (int, int, int, int,
+ _BitInt (3) sb3_0, char, char, char,
+ char, char, char, char, char,
+ char,char,char,char,
+ _BitInt (5), _BitInt (5), short, short, char,
+ short, short, char, int,
+ int, int, int, int, char,
+ long, long, long, long, long,
+ long, char, char, char, __int128,
+ __int128, __int128, __int128, __int128,
+ __int128, char, _BitInt (129), _BitInt (129),
+ _BitInt (255), _BitInt (255), _BitInt (256), _BitInt (256),
+ _BitInt (257), _BitInt (257), _BitInt (511), _BitInt (511),
+ _BitInt (512), _BitInt (512), _BitInt (513), _BitInt (513),
+ _BitInt (1023), _BitInt (1023), _BitInt (1024),
+ _BitInt (1024), _BitInt (1025), _BitInt (1025), _BitInt (331),
+ _BitInt (331), _BitInt (412), _BitInt (412), _BitInt (985),
+ _BitInt (985), _BitInt (60692), _BitInt (60692), char, char,
+ char, char, short, short, char, char, short, short, unsigned,
+ int, v64s8, v64s8, v64s16, v64s16, v64s32, v64s32, long, long,
+ v128s8, v128s8, short, v128s16, int, v128s32, long, v128s64,
+ __int128, __int128, v256s8, v256s8, v256s16, v256s16, v256s32,
+ v256s32, v256s64, v256s64, v256s128, v256s128, v512s8, v512s8,
+ v512s16, v512s16, v512s32, v512s32, v512s64, v512s64,
+ v512s128, v512s128, char *ret)
+{
+ *ret = sb3_0;
+}
+
+void xprintf(const char *s, ...)
+{
+ __builtin_va_list arg;
+ __builtin_va_start(arg, s);
+ int x = __builtin_va_arg(arg, int);
+ if (x != 0xfc)
+ __builtin_abort();
+ __builtin_va_end(arg);
+}
+
+int
+main ()
+{
+ char x;
+ foo0 (0, 0, 0, 0, -4, 0, 0, 3, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11, 9, 2, 95,
+ 67, -24064, 0, 5, 6, 7, 0, 8, 9, 20, 4, 3, 6018427387903, 53,
+ 505857273496, 255, 6, 0, 18446744073709551612uwb,
+ 70141183460469231731687303715884105726uwb,
+ 0x1ab7415df78c5d6355b5bf722d2c32wb, 18266202578652419339uwb,
+ 9594516560314871492uwb, 18446744073709551615uwb, 0,
+ 404678514476015038251338572701189uwb, 0,
+
6044618658097711785492504343953926634992332820282019728792003956564819964uwb,
+ 0, 0,
+
6044618658097711785492504343953926634992332820282019728792003956564819967uwb,
+ 0,
+ 0x10000000000000000000000000000000000000000000000000000000000000000wb,
0, 1, 0, 606316039853739674053402528525595147334676uwb, 0,
+
407807929942597099574024998205846127479363981533648751059337645126787177315524892796678197877342278766808798337256961671307362116160553321514205699439425uwb,
+ 0,
+
40449424473557664318357520289433168951375240783177119330601884005280028469967848339414697442203604155532867238014401323013014363877264556147687333148794044698496604162935270824544179699376777403364901791967663653826658703420189949487003960239619175525152082242122474284732uwb,
+
90772930519078902473361797697894230657273430081157732675805500963132708477322407536021120113879871393357658789768814416622492847430639474124377767893424865485276302219601246094119453082952085005768838150682342462881473913110540827237163350510684586298239947245938479716304835356329623282435531uwb,
+ 0, 0,
+
30203714894603546035770925859109268843954143792619895153655326951406405759993601526034894524347802740350892957243539456uwb,
+ 0,
+
0x24c07bd236a355dac41c3e00fed83a2c01d47d7e7c155128f8474ab8acd075fe3be2661e9ba3b0498c2wb,
+ 0,
+
-0x273d7a44735564a706be6f876e8c09a64c065028fc8719feace6b4ad22b722fc6628809c1bcfda902d563717b88876aa068496bwb,
+ 0, 5, 0, 4, 0, 5, 0, 0115, 3, 92, 0, 1, 840, 839, 35, 4095, (v64s8)
+ { }, (v64s8)
+ { 3, -0x4 }, (v64s16)
+ { }, (v64s16)
+ { }, (v64s32)
+ { }, (v64s32)
+ { }, 7, 40, (v128s8)
+ { }, (v128s8)
+ { }, 126, (v128s16)
+ { }, 95, (v128s32)
+ { }, 6, (v128s64)
+ { }, 18446462603027742720uwb, 11842991817553718011uwb, (v256s8)
+ { 227, 84, 73, 5, 2, 45, 107, 55, 16, 128, 23, 17, 1, 226, 15 },
+ (v256s8)
+ { 9, 111, 108, 19, 98, 27, 97, -0xe }, (v256s16)
+ { 1, 167, 65280, 35, 15286, 9, 182, 13126, 15 }, (v256s16)
+ { 72, 381, 185, 619, 978, 926, 42 }, (v256s32)
+ { 20, 72, 905, 207, 63, 40 }, (v256s32)
+ { 5, 503, 1, 152, 5519391 }, (v256s64)
+ { 1280 }, (v256s64)
+ { 94, 8851183291103289765uwb, 526 }, (v256s128)
+ { 15013856701581711399uwb }, (v256s128)
+ { 10389555769421265252uwb, 15766594437788011035uwb }, (v512s8)
+ { 104, 131, 5, 21, 32, 127, 75, 54, 232, 1, 82, 255, 28, 178, 1,
+ 121, 1, 14, 210, 240, 140, 53, 4, 91, 204, 78, 130, 76, 212, 52, 1,
+ 200, 11, 25, 251, 41, 88, 12, 3, 59 }, (v512s8)
+ { 13, 10, 48, -0x2f, 67, 85, 87, 123, 8, 26, 83, 114, 51, 6, 96,
+ -0x1c, 115, 49, 86, 103, 93, 31, -0x6, 112, 1, 7, -0xc, 18, 47, 5,
+ -0xf, 3 }, (v512s16)
+ { 4094, 64492, 855, 61680, 27, 47569, 55, 65534, 76, -1024, 30,
+ 254, 280, 11, 10, 14, 2, 4095, 3, 111, 65535, 67, 24289, 32, 25604,
+ 26, 65535, 98, 65533, 5 }, (v512s16)
+ { 615, 2032, 54, 52, 015, 45, 24, 6, 7, 68, 24015, 380, 3315, 5, 8,
+ 23, -0xf, 62, 82, 4 }, (v512s32)
+ { 54, 4294967294, 6, 16, 9, 13, 300, 80000000, 700, 600, 93, 040,
+ 15 }, (v512s32)
+ { 515, 3, 14, 10, 2, 80, 39, 215, 7, 3, 4 }, (v512s64)
+ { 4, 9, 5, 3, 505 }, (v512s64)
+ { 904293909041052234uwb, 4 }, (v512s128)
+ { 9223372036854775808uwb, 1, 4073709551612 }, (v512s128)
+ { 7, 30391054, 18446742974197923807uwb }, &x);
+ for (unsigned i = 0; i < sizeof(x); i++) xprintf("%02x", (int)(unsigned
char)x);
+}
--
2.53.0
