[Bug rtl-optimization/82889] New: Unnecessary sign extension of int32 to int64

[hiraditya at msn dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82889

            Bug ID: 82889
           Summary: Unnecessary sign extension of int32 to int64
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hiraditya at msn dot com
  Target Milestone: ---

$ cat t.cpp
#include <stdint.h>

int lol(int32_t* table, int32_t* ht, uint32_t hash, uint32_t mask) {
    for (uint64_t probe = (uint32_t)hash & mask, i = 1;; ++i) {
        int32_t pos = ht[probe];
        if (pos >= 0) {
            if (table[pos] == 42) {
                return true;
            }
        } else if (pos & 1) {
            return false;
        }
        probe += i;
        probe &= mask;
    }
    // notreached
}

compile with:
gcc -std=c++11 -O3 -s -o -


lol(int*, int*, unsigned int, unsigned int):
        andl    %ecx, %edx
        movl    $1, %r8d
        movl    %ecx, %ecx
        jmp     .L5
.L10:
        cmpl    $42, (%rdi,%rax,4)
        je      .L9
.L4:
        addq    %r8, %rdx
        addq    $1, %r8
        andq    %rcx, %rdx
.L5:
        movslq  (%rsi,%rdx,4), %rax #<------------sign extended
        testl   %eax, %eax
        jns     .L10
        testb   $1, %al
        je      .L4
        xorl    %eax, %eax
        ret
.L9:
        movl    $1, %eax
        ret


Is it possible to get rid of this?