https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83479
Bug ID: 83479
Summary: Register spilling in AVX code
Product: gcc
Version: 7.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: bugzi...@poradnik-webmastera.com
Target Milestone: ---
Here is snipped of code which performs some calculations on matrix. It
repeatedly transforms some (N * N) matrix into (N-1 * N-1) one, and returns
final scalar value. gcc for some reason is not able to detect that intermediate
values are not needed anymore, and starts spilling. Code below is from gcc 7.2,
trunk version also generates similar code. Code was compiled with "-O3
-march=haswell".
BTW, clang 5 properly handles this and does not spill.
[code]
#include "immintrin.h"
double test(const double data[9][8])
{
__m256d vLastRow, vLastCol, vSqrtRow, vSqrtCol;
__m256d v1 = _mm256_load_pd (&data[0][0]);
__m256d v2 = _mm256_load_pd (&data[1][0]);
__m256d v3 = _mm256_load_pd (&data[2][0]);
__m256d v4 = _mm256_load_pd (&data[3][0]);
__m256d v5 = _mm256_load_pd (&data[4][0]);
__m256d v6 = _mm256_load_pd (&data[5][0]);
__m256d v7 = _mm256_load_pd (&data[6][0]);
__m256d v8 = _mm256_load_pd (&data[7][0]);
// 8
vLastRow = _mm256_load_pd (&data[9][0]);
vSqrtRow = _mm256_sqrt_pd(vLastRow);
vLastCol = _mm256_set1_pd(vLastRow[0]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v1 = (v1 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[1]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v2 = (v2 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[2]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v3 = (v3 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[3]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v4 = (v4 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[4]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v5 = (v5 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[5]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v6 = (v6 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[6]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v7 = (v7 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[7]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v8 = (v8 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
// 7
vLastRow = v8;
vSqrtRow = _mm256_sqrt_pd(vLastRow);
vLastCol = _mm256_set1_pd(vLastRow[0]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v1 = (v1 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[1]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v2 = (v2 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[2]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v3 = (v3 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[3]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v4 = (v4 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[4]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v5 = (v5 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[5]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v6 = (v6 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[6]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v7 = (v7 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
// 6
vLastRow = v7;
vSqrtRow = _mm256_sqrt_pd(vLastRow);
vLastCol = _mm256_set1_pd(vLastRow[0]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v1 = (v1 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[1]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v2 = (v2 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[2]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v3 = (v3 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[3]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v4 = (v4 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[4]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v5 = (v5 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[5]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v6 = (v6 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
// 5
vLastRow = v6;
vSqrtRow = _mm256_sqrt_pd(vLastRow);
vLastCol = _mm256_set1_pd(vLastRow[0]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v1 = (v1 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[1]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v2 = (v2 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[2]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v3 = (v3 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[3]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v4 = (v4 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[4]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v5 = (v5 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
// 4
vLastRow = v5;
vSqrtRow = _mm256_sqrt_pd(vLastRow);
vLastCol = _mm256_set1_pd(vLastRow[0]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v1 = (v1 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[1]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v2 = (v2 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[2]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v3 = (v3 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[3]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v4 = (v4 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
// 3
vLastRow = v4;
vSqrtRow = _mm256_sqrt_pd(vLastRow);
vLastCol = _mm256_set1_pd(vLastRow[0]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v1 = (v1 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[1]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v2 = (v2 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[2]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v3 = (v3 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
// 2
vLastRow = v3;
vSqrtRow = _mm256_sqrt_pd(vLastRow);
vLastCol = _mm256_set1_pd(vLastRow[0]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v1 = (v1 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
vLastCol = _mm256_set1_pd(vLastRow[1]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v2 = (v2 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
// 1
vLastRow = v2;
vSqrtRow = _mm256_sqrt_pd(vLastRow);
vLastCol = _mm256_set1_pd(vLastRow[0]);
vSqrtCol = _mm256_sqrt_pd(vLastCol);
v1 = (v1 - vLastRow * vLastCol) * vSqrtRow * vSqrtCol;
return v1[0];
}
[/code]
[out]
test(double const (*) [8]):
lea r10, [rsp+8]
and rsp, -32
push QWORD PTR [r10-8]
push rbp
mov rbp, rsp
push r10
sub rsp, 1040
vmovapd ymm7, YMMWORD PTR [rdi+576]
vbroadcastsd ymm0, QWORD PTR [rbp-16]
vpermpd ymm2, ymm7, 0
vsqrtpd ymm15, ymm7
vpermpd ymm12, ymm7, 255
vsqrtpd ymm5, ymm2
vsqrtpd ymm4, ymm12
vmovapd YMMWORD PTR [rbp-560], ymm2
vsqrtpd ymm2, ymm0
vmovapd YMMWORD PTR [rbp-592], ymm5
vpermpd ymm5, ymm7, 85
vmovapd YMMWORD PTR [rbp-528], ymm5
vsqrtpd ymm6, ymm5
vbroadcastsd ymm5, QWORD PTR [rbp+8]
vmovapd YMMWORD PTR [rbp-208], ymm4
vbroadcastsd ymm4, QWORD PTR [rbp+0]
vmovapd ymm14, ymm5
vsqrtpd ymm9, ymm5
vfnmadd213pd ymm14, ymm7, YMMWORD PTR [rdi+448]
vsqrtpd ymm8, ymm4
vmovapd YMMWORD PTR [rbp-624], ymm6
vpermpd ymm6, ymm7, 170
vmovapd YMMWORD PTR [rbp-496], ymm6
vsqrtpd ymm1, ymm6
vmulpd ymm6, ymm14, ymm15
vmovapd YMMWORD PTR [rbp-656], ymm1
vbroadcastsd ymm1, QWORD PTR [rbp-8]
vsqrtpd ymm3, ymm1
vmulpd ymm6, ymm6, ymm9
vpermpd ymm13, ymm6, 0
vsqrtpd ymm14, ymm6
vsqrtpd ymm10, ymm13
vmovapd YMMWORD PTR [rbp-464], ymm13
vpermpd ymm13, ymm6, 170
vmovapd YMMWORD PTR [rbp-688], ymm10
vpermpd ymm10, ymm6, 85
vsqrtpd ymm11, ymm10
vmovapd YMMWORD PTR [rbp-432], ymm10
vmovapd YMMWORD PTR [rbp-720], ymm11
vsqrtpd ymm11, ymm13
vmulpd ymm13, ymm6, ymm13
vmovapd YMMWORD PTR [rbp-752], ymm11
vpermpd ymm11, ymm6, 255
vsqrtpd ymm9, ymm11
vmovapd YMMWORD PTR [rbp-144], ymm11
vmovapd YMMWORD PTR [rbp-784], ymm9
vmulpd ymm9, ymm6, ymm4
vfnmadd213pd ymm4, ymm7, YMMWORD PTR [rdi+384]
vmulpd ymm4, ymm4, ymm15
vfmsub132pd ymm4, ymm9, ymm8
vmulpd ymm5, ymm4, ymm14
vmulpd ymm5, ymm5, ymm8
vpermpd ymm4, ymm5, 0
vsqrtpd ymm11, ymm5
vpermpd ymm10, ymm5, 255
vsqrtpd ymm8, ymm4
vmovapd YMMWORD PTR [rbp-400], ymm4
vmovapd YMMWORD PTR [rbp-816], ymm8
vpermpd ymm8, ymm5, 85
vsqrtpd ymm9, ymm8
vmovapd YMMWORD PTR [rbp-368], ymm8
vsqrtpd ymm8, ymm10
vmulpd ymm10, ymm10, ymm5
vmovapd YMMWORD PTR [rbp-848], ymm9
vpermpd ymm9, ymm5, 170
vsqrtpd ymm4, ymm9
vmovapd YMMWORD PTR [rbp-176], ymm9
vfnmadd213pd ymm12, ymm7, YMMWORD PTR [rdi+192]
vmovapd YMMWORD PTR [rbp-912], ymm8
vmulpd ymm8, ymm1, ymm5
vmovapd YMMWORD PTR [rbp-80], ymm14
vmulpd ymm9, ymm6, ymm0
vmovapd YMMWORD PTR [rbp-880], ymm4
vmulpd ymm4, ymm6, ymm1
vfnmadd213pd ymm1, ymm7, YMMWORD PTR [rdi+320]
vmulpd ymm1, ymm1, ymm15
vfmsub231pd ymm4, ymm1, ymm3
vmulpd ymm4, ymm4, ymm14
vmovapd ymm14, ymm11
vmovapd YMMWORD PTR [rbp-112], ymm14
vfmsub132pd ymm4, ymm8, ymm3
vmulpd ymm4, ymm4, ymm11
vmulpd ymm4, ymm4, ymm3
vpermpd ymm1, ymm4, 0
vpermpd ymm11, ymm4, 170
vpermpd ymm8, ymm4, 255
vsqrtpd ymm3, ymm1
vmovapd YMMWORD PTR [rbp-336], ymm1
vmovapd YMMWORD PTR [rbp-944], ymm3
vpermpd ymm3, ymm4, 85
vsqrtpd ymm1, ymm3
vmovapd YMMWORD PTR [rbp-304], ymm3
vmulpd ymm3, ymm0, ymm4
vmovapd YMMWORD PTR [rbp-976], ymm1
vsqrtpd ymm1, ymm11
vmulpd ymm11, ymm11, ymm4
vmovapd YMMWORD PTR [rbp-1008], ymm1
vsqrtpd ymm1, ymm8
vmulpd ymm8, ymm8, ymm4
vmovapd YMMWORD PTR [rbp-1040], ymm1
vmulpd ymm1, ymm0, ymm5
vfnmadd213pd ymm0, ymm7, YMMWORD PTR [rdi+256]
vmulpd ymm0, ymm0, ymm15
vfmsub231pd ymm9, ymm0, ymm2
vmulpd ymm9, ymm9, YMMWORD PTR [rbp-80]
vmulpd ymm0, ymm12, ymm15
vmovapd ymm12, YMMWORD PTR [rbp-1040]
vfmsub231pd ymm1, ymm9, ymm2
vmulpd ymm1, ymm1, ymm14
vsqrtpd ymm14, ymm4
vfmsub132pd ymm1, ymm3, ymm2
vmulpd ymm1, ymm1, ymm14
vmulpd ymm1, ymm1, ymm2
vpermpd ymm2, ymm1, 0
vpermpd ymm9, ymm1, 85
vsqrtpd ymm3, ymm2
vmovapd YMMWORD PTR [rbp-272], ymm2
vsqrtpd ymm2, ymm9
vmovapd YMMWORD PTR [rbp-240], ymm9
vpermpd ymm9, ymm1, 170
vmovapd YMMWORD PTR [rbp-1072], ymm3
vsqrtpd ymm3, ymm9
vmovapd YMMWORD PTR [rbp-1104], ymm2
vmulpd ymm9, ymm9, ymm1
vmovapd YMMWORD PTR [rbp-1136], ymm3
vpermpd ymm3, ymm1, 255
vsqrtpd ymm2, ymm3
vmulpd ymm3, ymm3, ymm1
vmovapd YMMWORD PTR [rbp-1168], ymm2
vmulpd ymm2, ymm6, YMMWORD PTR [rbp-144]
vfmsub132pd ymm0, ymm2, YMMWORD PTR [rbp-208]
vmovapd YMMWORD PTR [rbp-144], ymm14
vmulpd ymm0, ymm0, YMMWORD PTR [rbp-80]
vfmsub132pd ymm0, ymm10, YMMWORD PTR [rbp-784]
vmulpd ymm0, ymm0, YMMWORD PTR [rbp-112]
vfmsub132pd ymm0, ymm8, YMMWORD PTR [rbp-912]
vmulpd ymm0, ymm0, ymm14
vsqrtpd ymm14, ymm1
vfmsub132pd ymm12, ymm3, ymm0
vmulpd ymm2, ymm12, ymm14
vmulpd ymm2, ymm2, YMMWORD PTR [rbp-1168]
vsqrtpd ymm10, ymm2
vpermpd ymm12, ymm2, 0
vmovapd YMMWORD PTR [rbp-208], ymm12
vmovapd YMMWORD PTR [rbp-784], ymm10
vsqrtpd ymm10, ymm12
vmovapd YMMWORD PTR [rbp-912], ymm10
vpermpd ymm10, ymm2, 85
vsqrtpd ymm8, ymm10
vmulpd ymm10, ymm10, ymm2
vmovapd YMMWORD PTR [rbp-1040], ymm8
vmovapd ymm0, YMMWORD PTR [rbp-496]
vpermpd ymm8, ymm2, 170
vfnmadd213pd ymm0, ymm7, YMMWORD PTR [rdi+128]
vmulpd ymm3, ymm5, YMMWORD PTR [rbp-176]
vsqrtpd ymm12, ymm8
vmovapd YMMWORD PTR [rbp-176], ymm14
vmulpd ymm8, ymm8, ymm2
vmulpd ymm0, ymm0, ymm15
vfmsub132pd ymm0, ymm13, YMMWORD PTR [rbp-656]
vmulpd ymm0, ymm0, YMMWORD PTR [rbp-80]
vfmsub132pd ymm0, ymm3, YMMWORD PTR [rbp-752]
vmovapd ymm3, YMMWORD PTR [rbp-784]
vmulpd ymm0, ymm0, YMMWORD PTR [rbp-112]
vfmsub132pd ymm0, ymm11, YMMWORD PTR [rbp-880]
vmovapd ymm11, YMMWORD PTR [rbp-1136]
vmulpd ymm0, ymm0, YMMWORD PTR [rbp-144]
vfmsub132pd ymm0, ymm9, YMMWORD PTR [rbp-1008]
vmulpd ymm0, ymm0, ymm14
vmulpd ymm14, ymm5, YMMWORD PTR [rbp-368]
vfmsub132pd ymm11, ymm8, ymm0
vmulpd ymm0, ymm4, YMMWORD PTR [rbp-304]
vmovapd YMMWORD PTR [rbp-304], ymm14
vmulpd ymm3, ymm3, ymm11
vmulpd ymm3, ymm3, ymm12
vmulpd ymm12, ymm1, YMMWORD PTR [rbp-240]
vmovapd YMMWORD PTR [rbp-240], ymm0
vmulpd ymm0, ymm6, YMMWORD PTR [rbp-432]
vpermpd ymm8, ymm3, 0
vsqrtpd ymm13, ymm3
vpermpd ymm9, ymm3, 85
vsqrtpd ymm11, ymm8
vmovapd ymm14, ymm0
vmovapd ymm0, YMMWORD PTR [rbp-528]
vfnmadd213pd ymm0, ymm7, YMMWORD PTR [rdi+64]
vmovapd YMMWORD PTR [rbp-496], ymm11
vsqrtpd ymm11, ymm9
vmulpd ymm9, ymm9, ymm3
vmulpd ymm0, ymm0, ymm15
vfmsub132pd ymm0, ymm14, YMMWORD PTR [rbp-624]
vmovapd ymm14, YMMWORD PTR [rbp-304]
vmulpd ymm0, ymm0, YMMWORD PTR [rbp-80]
vfmsub132pd ymm0, ymm14, YMMWORD PTR [rbp-720]
vmovapd ymm14, YMMWORD PTR [rbp-240]
vmulpd ymm0, ymm0, YMMWORD PTR [rbp-112]
vfmsub132pd ymm0, ymm14, YMMWORD PTR [rbp-848]
vsqrtpd ymm14, ymm2
vmulpd ymm0, ymm0, YMMWORD PTR [rbp-144]
vfmsub132pd ymm0, ymm12, YMMWORD PTR [rbp-976]
vmulpd ymm0, ymm0, YMMWORD PTR [rbp-176]
vfmsub132pd ymm0, ymm10, YMMWORD PTR [rbp-1104]
vmulpd ymm6, ymm6, YMMWORD PTR [rbp-464]
vmulpd ymm5, ymm5, YMMWORD PTR [rbp-400]
vmulpd ymm4, ymm4, YMMWORD PTR [rbp-336]
vmulpd ymm1, ymm1, YMMWORD PTR [rbp-272]
vmulpd ymm0, ymm0, ymm14
vfmsub132pd ymm0, ymm9, YMMWORD PTR [rbp-1040]
vmulpd ymm2, ymm2, YMMWORD PTR [rbp-208]
vmulpd ymm3, ymm8, ymm3
vmulpd ymm0, ymm0, ymm13
vmulpd ymm11, ymm0, ymm11
vpermpd ymm0, ymm11, 0
vsqrtpd ymm12, ymm11
vmulpd ymm11, ymm0, ymm11
vsqrtpd ymm10, ymm0
vmovapd ymm0, YMMWORD PTR [rbp-560]
vfnmadd213pd ymm7, ymm0, YMMWORD PTR [rdi]
vmulpd ymm7, ymm7, ymm15
vfmsub132pd ymm7, ymm6, YMMWORD PTR [rbp-592]
vmulpd ymm7, ymm7, YMMWORD PTR [rbp-80]
vfmsub132pd ymm7, ymm5, YMMWORD PTR [rbp-688]
vmulpd ymm7, ymm7, YMMWORD PTR [rbp-112]
vfmsub132pd ymm7, ymm4, YMMWORD PTR [rbp-816]
vmulpd ymm0, ymm7, YMMWORD PTR [rbp-144]
vfmsub132pd ymm0, ymm1, YMMWORD PTR [rbp-944]
vmulpd ymm0, ymm0, YMMWORD PTR [rbp-176]
vfmsub132pd ymm0, ymm2, YMMWORD PTR [rbp-1072]
vmulpd ymm0, ymm0, ymm14
vfmsub132pd ymm0, ymm3, YMMWORD PTR [rbp-912]
vmulpd ymm0, ymm0, ymm13
vfmsub132pd ymm0, ymm11, YMMWORD PTR [rbp-496]
vmulpd ymm0, ymm0, ymm12
vmulpd ymm0, ymm0, ymm10
vzeroupper
add rsp, 1040
pop r10
pop rbp
lea rsp, [r10-8]
ret
[/out]
