416.gamess regressed 4-6% on x86_64 since my r15-882-g1d6199e5f8c1c0. The commit adjust rtx_cost of mem to reduce cost of (add op0 disp). But Cost of ADDR could be cheaper than XEXP (addr, 0) when it's a lea. It is the case in the PR, the patch uses lower cost to enable more simplication and fix the regression.
Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}. Ok for trunk? gcc/ChangeLog: PR target/115462 * config/i386/i386.cc (ix86_rtx_costs): Use cost of addr when it's lower than rtx_cost (XEXP (addr, 0)) + 1. gcc/testsuite/ChangeLog: * gcc.target/i386/pr115462.c: New test. --- gcc/config/i386/i386.cc | 9 +++++++-- gcc/testsuite/gcc.target/i386/pr115462.c | 22 ++++++++++++++++++++++ 2 files changed, 29 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/gcc.target/i386/pr115462.c diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc index d4ccc24be6e..83dab8220dd 100644 --- a/gcc/config/i386/i386.cc +++ b/gcc/config/i386/i386.cc @@ -22341,8 +22341,13 @@ ix86_rtx_costs (rtx x, machine_mode mode, int outer_code_i, int opno, if (GET_CODE (addr) == PLUS && x86_64_immediate_operand (XEXP (addr, 1), Pmode)) { - *total += 1; - *total += rtx_cost (XEXP (addr, 0), Pmode, PLUS, 0, speed); + /* PR115462: Cost of ADDR could be cheaper than XEXP (addr, 0) + when it's a lea, use lower cost to enable more + simplification. */ + unsigned cost1 = rtx_cost (addr, Pmode, MEM, 0, speed); + unsigned cost2 = rtx_cost (XEXP (addr, 0), Pmode, + PLUS, 0, speed) + 1; + *total += MIN (cost1, cost2); return true; } } diff --git a/gcc/testsuite/gcc.target/i386/pr115462.c b/gcc/testsuite/gcc.target/i386/pr115462.c new file mode 100644 index 00000000000..ad50a6382bc --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr115462.c @@ -0,0 +1,22 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -mavx2 -fno-tree-vectorize -fno-pic" } */ +/* { dg-final { scan-assembler-times {(?n)movl[ \t]+.*, p1\.0\+[0-9]*\(,} 3 } } */ + +int +foo (long indx, long indx2, long indx3, long indx4, long indx5, long indx6, long n, int* q) +{ + static int p1[10000]; + int* p2 = p1 + 1000; + int* p3 = p1 + 4000; + int* p4 = p1 + 8000; + + for (long i = 0; i != n; i++) + { + /* scan for movl %edi, p1.0+3996(,%rax,4), + p1.0+3996 should be propagted into the loop. */ + p2[indx++] = q[indx++]; + p3[indx2++] = q[indx2++]; + p4[indx3++] = q[indx3++]; + } + return p1[indx6] + p1[indx5]; +} -- 2.31.1