[llvm-bugs] [Bug 26245] New: [AArch64] Lots of redundant 'adrp' instructions

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https://llvm.org/bugs/show_bug.cgi?id=26245

            Bug ID: 26245
           Summary: [AArch64] Lots of redundant 'adrp' instructions
           Product: libraries
           Version: trunk
          Hardware: PC
                OS: Windows NT
            Status: NEW
          Severity: normal
          Priority: P
         Component: Backend: AArch64
          Assignee: unassignedbugs at nondot.org
          Reporter: mcrosier at codeaurora.org
                CC: bmakam at codeaurora.org, gberry at codeaurora.org,
                    haicheng at codeaurora.org, junbuml at codeaurora.org,
                    llvm-bugs at lists.llvm.org, mcrosier at codeaurora.org,
                    mssimpso at codeaurora.org
    Classification: Unclassified

I see lots of cases were we have redundant 'adrp' instructions.  For example, I
just ran into something like the following:

 adrp x8, 541000
 str d1, [sp,#40]
 ldr d1, [x8,#2392]
 adrp x9, 541000     // Redundant
 adrp x21, 5d3000
 str d1, [sp,#32]
 ldr d1, [x9,#2800]
 mov x19, x0
 str wzr, [x19,#16]
 stp xzr, xzr, [x19]
 str wzr, [sp,#20]
 fmov s15, wzr
 mov v4.16b, v15.16b
 mov v5.16b, v15.16b
 mov v6.16b, v15.16b
 mov v7.16b, v15.16b
 mov v16.16b, v15.16b
 mov v13.16b, v15.16b
 mov v14.16b, v15.16b
 fmov d8, #-5.000000000000e-01
 adrp x23, 5d3000    // Potentially redundant
 mov w22, wzr
 add x23, x23, #0xfc0
 adrp x24, 5d0000
 str d1, [sp,#24]
 ldp d9, d12, [sp,#24]
 adrp x26, 5d0000   // Redundant
 add x26, x26, #0x9c8

I'll see if I can't reduce a test case shortly.

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