https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99409
Bug ID: 99409
Summary: s252 benchmark of TSVC is vectorized by clang and not
by gcc
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: hubicka at gcc dot gnu.org
Target Milestone: ---
typedef float real_t;
#define iterations 100000
#define LEN_1D 32000
#define LEN_2D 256
real_t a[LEN_1D],b[LEN_1D],c[LEN_1D],d[LEN_1D],e[LEN_1D];
void main()
{
// scalar and array expansion
// loop with ambiguous scalar temporary
real_t t, s;
for (int nl = 0; nl < iterations; nl++) {
t = (real_t) 0.;
for (int i = 0; i < LEN_1D; i++) {
s = b[i] * c[i];
a[i] = s + t;
t = s;
}
}
}
clang does:
main: # @main
.cfi_startproc
# %bb.0:
xorl %eax, %eax
.p2align 4, 0x90
.LBB0_1: # =>This Loop Header: Depth=1
# Child Loop BB0_2 Depth 2
vxorps %xmm0, %xmm0, %xmm0
movq $-128000, %rcx # imm = 0xFFFE0C00
.p2align 4, 0x90
.LBB0_2: # Parent Loop BB0_1 Depth=1
# => This Inner Loop Header: Depth=2
vmovups c+128000(%rcx), %ymm1
vmovups c+128032(%rcx), %ymm2
vmovups c+128064(%rcx), %ymm3
vmovups c+128096(%rcx), %ymm4
vmulps b+128000(%rcx), %ymm1, %ymm1
vmulps b+128032(%rcx), %ymm2, %ymm2
vmulps b+128064(%rcx), %ymm3, %ymm3
vmulps b+128096(%rcx), %ymm4, %ymm4
vperm2f128 $33, %ymm1, %ymm0, %ymm0 # ymm0 = ymm0[2,3],ymm1[0,1]
vperm2f128 $33, %ymm2, %ymm1, %ymm5 # ymm5 = ymm1[2,3],ymm2[0,1]
vperm2f128 $33, %ymm3, %ymm2, %ymm6 # ymm6 = ymm2[2,3],ymm3[0,1]
vperm2f128 $33, %ymm4, %ymm3, %ymm7 # ymm7 = ymm3[2,3],ymm4[0,1]
vshufps $3, %ymm1, %ymm0, %ymm0 # ymm0 =
ymm0[3,0],ymm1[0,0],ymm0[7,4],ymm1[4,4]
vshufps $3, %ymm2, %ymm5, %ymm5 # ymm5 =
ymm5[3,0],ymm2[0,0],ymm5[7,4],ymm2[4,4]
vshufps $3, %ymm3, %ymm6, %ymm6 # ymm6 =
ymm6[3,0],ymm3[0,0],ymm6[7,4],ymm3[4,4]
vshufps $3, %ymm4, %ymm7, %ymm7 # ymm7 =
ymm7[3,0],ymm4[0,0],ymm7[7,4],ymm4[4,4]
vshufps $152, %ymm1, %ymm0, %ymm0 # ymm0 =
ymm0[0,2],ymm1[1,2],ymm0[4,6],ymm1[5,6]
vshufps $152, %ymm2, %ymm5, %ymm5 # ymm5 =
ymm5[0,2],ymm2[1,2],ymm5[4,6],ymm2[5,6]
vshufps $152, %ymm3, %ymm6, %ymm6 # ymm6 =
ymm6[0,2],ymm3[1,2],ymm6[4,6],ymm3[5,6]
vshufps $152, %ymm4, %ymm7, %ymm7 # ymm7 =
ymm7[0,2],ymm4[1,2],ymm7[4,6],ymm4[5,6]
vaddps %ymm0, %ymm1, %ymm0
vaddps %ymm5, %ymm2, %ymm1
vaddps %ymm6, %ymm3, %ymm2
vaddps %ymm7, %ymm4, %ymm3
vmovups %ymm0, a+128000(%rcx)
vmovups %ymm1, a+128032(%rcx)
vmovups %ymm2, a+128064(%rcx)
vmovups %ymm3, a+128096(%rcx)
subq $-128, %rcx
vmovaps %ymm4, %ymm0
jne .LBB0_2
# %bb.3: # in Loop: Header=BB0_1 Depth=1
incl %eax
cmpl $100000, %eax # imm = 0x186A0
jne .LBB0_1
# %bb.4:
vzeroupper
retq
s252.c:18:27: note: worklist: examine stmt: _3 = s_11 + t_21;
s252.c:18:27: note: vect_is_simple_use: operand _1 * _2, type of def:
internal
s252.c:18:27: note: mark relevant 5, live 0: s_11 = _1 * _2;
s252.c:18:27: note: vect_is_simple_use: operand t_21 = PHI <s_11(8), 0.0(5)>,
type of def: unknown
s252.c:18:27: missed: Unsupported pattern.
s252.c:20:22: missed: not vectorized: unsupported use in stmt.
s252.c:18:27: missed: unexpected pattern.
<bb 8> [local count: 1052266996]:
<bb 3> [local count: 1063004409]:
# t_21 = PHI <s_11(8), 0.0(5)>
# i_23 = PHI <i_13(8), 0(5)>
# ivtmp_20 = PHI <ivtmp_19(8), 32000(5)>
_1 = b[i_23];
_2 = c[i_23];
s_11 = _1 * _2;
_3 = s_11 + t_21;
a[i_23] = _3;
i_13 = i_23 + 1;
ivtmp_19 = ivtmp_20 - 1;
if (ivtmp_19 != 0)
goto <bb 8>; [98.99%]
else
goto <bb 4>; [1.01%]
