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From: "already5chosen at yahoo dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/105617] New: Regression in code generation for _addcarry_u64() Date: Mon, 16 May 2022 12:08:56 +0000 [thread overview] Message-ID: <bug-105617-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105617 Bug ID: 105617 Summary: Regression in code generation for _addcarry_u64() Product: gcc Version: 12.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: already5chosen at yahoo dot com Target Milestone: --- It took many years until gcc caught up with MSVC and LLVM/clang in generation of code for chains of Intel's _addcarry_u64() intrinsic calls. But your finally managed to do it in gcc11. Unfortunately, the luck didn't last for long. void add4i(uint64_t dst[4], const uint64_t srcA[4], const uint64_t srcB[4]) { unsigned char c; unsigned long long r0; c = _addcarry_u64(0, srcA[0], srcB[0], &r0); unsigned long long r1; c = _addcarry_u64(c, srcA[1], srcB[1], &r1); unsigned long long r2; c = _addcarry_u64(c, srcA[2], srcB[2], &r2); unsigned long long r3; c = _addcarry_u64(c, srcA[3], srcB[3], &r3); dst[0] = r0; dst[1] = r1; dst[2] = r2; dst[3] = r3; } gcc 11.1 -O2 add4i: movq (%rdx), %rax addq (%rsi), %rax movq 8(%rsi), %rcx movq %rax, %r8 adcq 8(%rdx), %rcx movq 16(%rsi), %rax adcq 16(%rdx), %rax movq 24(%rdx), %rdx adcq 24(%rsi), %rdx movq %r8, (%rdi) movq %rcx, 8(%rdi) movq %rax, 16(%rdi) movq %rdx, 24(%rdi) ret gcc 12.1 -O2 add4i: movq (%rdx), %rax movq 8(%rsi), %rcx addq (%rsi), %rax movq 16(%rsi), %r8 adcq 8(%rdx), %rcx adcq 16(%rdx), %r8 movq %rax, %xmm1 movq 24(%rdx), %rdx adcq 24(%rsi), %rdx movq %r8, %xmm0 movq %rcx, %xmm3 movq %rdx, %xmm2 punpcklqdq %xmm3, %xmm1 punpcklqdq %xmm2, %xmm0 movups %xmm1, (%rdi) movups %xmm0, 16(%rdi) ret What ... ?! BTW, gcc 12.1 -O1 is still o.k.
next reply other threads:[~2022-05-16 12:08 UTC|newest] Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-05-16 12:08 already5chosen at yahoo dot com [this message] 2022-05-16 12:13 ` [Bug target/105617] [12/13 regressi] Slp is maybe too aggressive in some/many cases pinskia at gcc dot gnu.org 2022-05-16 12:14 ` pinskia at gcc dot gnu.org 2022-05-16 12:15 ` rguenth at gcc dot gnu.org 2022-05-16 12:38 ` [Bug target/105617] [12/13 Regression] " already5chosen at yahoo dot com 2022-05-16 13:02 ` already5chosen at yahoo dot com 2022-05-16 14:08 ` already5chosen at yahoo dot com 2022-05-17 2:47 ` crazylht at gmail dot com 2022-05-17 3:29 ` crazylht at gmail dot com 2022-05-17 3:37 ` crazylht at gmail dot com 2022-05-17 6:48 ` rguenth at gcc dot gnu.org 2022-05-17 9:17 ` already5chosen at yahoo dot com 2022-05-17 9:25 ` already5chosen at yahoo dot com 2022-05-19 8:05 ` crazylht at gmail dot com 2022-07-26 11:22 ` rguenth at gcc dot gnu.org 2022-07-26 11:22 ` rguenth at gcc dot gnu.org 2022-07-29 13:21 ` already5chosen at yahoo dot com 2023-05-08 12:24 ` [Bug target/105617] [12/13/14 " rguenth at gcc dot gnu.org 2023-06-01 7:58 ` slash.tmp at free dot fr 2023-06-07 23:16 ` already5chosen at yahoo dot com 2023-06-13 14:54 ` slash.tmp at free dot fr 2023-06-16 14:56 ` already5chosen at yahoo dot com
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