[llvm] r283862 - [AArch64] Allow label arithmetic with add/sub/cmp
Diana Picus via llvm-commits
llvm-commits at lists.llvm.org
Tue Oct 11 02:17:48 PDT 2016
Author: rovka
Date: Tue Oct 11 04:17:47 2016
New Revision: 283862
URL: http://llvm.org/viewvc/llvm-project?rev=283862&view=rev
Log:
[AArch64] Allow label arithmetic with add/sub/cmp
Allow instructions such as 'cmp w0, #(end - start)' by folding the
expression into a constant. For ELF, we fold only if the symbols are in
the same section. For MachO, we fold if the expression contains only
symbols that are not linker visible.
Fixes https://llvm.org/bugs/show_bug.cgi?id=18920
Differential Revision: https://reviews.llvm.org/D23834
Added:
llvm/trunk/test/MC/AArch64/label-arithmetic-darwin.s
llvm/trunk/test/MC/AArch64/label-arithmetic-diags-darwin.s
llvm/trunk/test/MC/AArch64/label-arithmetic-diags-elf.s
llvm/trunk/test/MC/AArch64/label-arithmetic-elf.s
Modified:
llvm/trunk/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp
llvm/trunk/test/MC/AArch64/basic-a64-diagnostics.s
Modified: llvm/trunk/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp?rev=283862&r1=283861&r2=283862&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp Tue Oct 11 04:17:47 2016
@@ -729,9 +729,13 @@ public:
|| ELFRefKind == AArch64MCExpr::VK_TLSDESC_LO12;
}
- // Otherwise it should be a real immediate in range:
- const MCConstantExpr *CE = cast<MCConstantExpr>(Expr);
- return CE->getValue() >= 0 && CE->getValue() <= 0xfff;
+ // If it's a constant, it should be a real immediate in range:
+ if (auto *CE = dyn_cast<MCConstantExpr>(Expr))
+ return CE->getValue() >= 0 && CE->getValue() <= 0xfff;
+
+ // If it's an expression, we hope for the best and let the fixup/relocation
+ // code deal with it.
+ return true;
}
bool isAddSubImmNeg() const {
if (!isShiftedImm() && !isImm())
@@ -3568,31 +3572,34 @@ bool AArch64AsmParser::validateInstructi
AArch64MCExpr::VariantKind ELFRefKind;
MCSymbolRefExpr::VariantKind DarwinRefKind;
int64_t Addend;
- if (!classifySymbolRef(Expr, ELFRefKind, DarwinRefKind, Addend)) {
- return Error(Loc[2], "invalid immediate expression");
- }
+ if (classifySymbolRef(Expr, ELFRefKind, DarwinRefKind, Addend)) {
- // Only allow these with ADDXri.
- if ((DarwinRefKind == MCSymbolRefExpr::VK_PAGEOFF ||
- DarwinRefKind == MCSymbolRefExpr::VK_TLVPPAGEOFF) &&
- Inst.getOpcode() == AArch64::ADDXri)
- return false;
+ // Only allow these with ADDXri.
+ if ((DarwinRefKind == MCSymbolRefExpr::VK_PAGEOFF ||
+ DarwinRefKind == MCSymbolRefExpr::VK_TLVPPAGEOFF) &&
+ Inst.getOpcode() == AArch64::ADDXri)
+ return false;
- // Only allow these with ADDXri/ADDWri
- if ((ELFRefKind == AArch64MCExpr::VK_LO12 ||
- ELFRefKind == AArch64MCExpr::VK_DTPREL_HI12 ||
- ELFRefKind == AArch64MCExpr::VK_DTPREL_LO12 ||
- ELFRefKind == AArch64MCExpr::VK_DTPREL_LO12_NC ||
- ELFRefKind == AArch64MCExpr::VK_TPREL_HI12 ||
- ELFRefKind == AArch64MCExpr::VK_TPREL_LO12 ||
- ELFRefKind == AArch64MCExpr::VK_TPREL_LO12_NC ||
- ELFRefKind == AArch64MCExpr::VK_TLSDESC_LO12) &&
- (Inst.getOpcode() == AArch64::ADDXri ||
- Inst.getOpcode() == AArch64::ADDWri))
- return false;
+ // Only allow these with ADDXri/ADDWri
+ if ((ELFRefKind == AArch64MCExpr::VK_LO12 ||
+ ELFRefKind == AArch64MCExpr::VK_DTPREL_HI12 ||
+ ELFRefKind == AArch64MCExpr::VK_DTPREL_LO12 ||
+ ELFRefKind == AArch64MCExpr::VK_DTPREL_LO12_NC ||
+ ELFRefKind == AArch64MCExpr::VK_TPREL_HI12 ||
+ ELFRefKind == AArch64MCExpr::VK_TPREL_LO12 ||
+ ELFRefKind == AArch64MCExpr::VK_TPREL_LO12_NC ||
+ ELFRefKind == AArch64MCExpr::VK_TLSDESC_LO12) &&
+ (Inst.getOpcode() == AArch64::ADDXri ||
+ Inst.getOpcode() == AArch64::ADDWri))
+ return false;
- // Don't allow expressions in the immediate field otherwise
- return Error(Loc[2], "invalid immediate expression");
+ // Don't allow symbol refs in the immediate field otherwise
+ // Note: Loc.back() may be Loc[1] or Loc[2] depending on the number of
+ // operands of the original instruction (i.e. 'add w0, w1, borked' vs
+ // 'cmp w0, 'borked')
+ return Error(Loc.back(), "invalid immediate expression");
+ }
+ // We don't validate more complex expressions here
}
return false;
}
Modified: llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp?rev=283862&r1=283861&r2=283862&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp Tue Oct 11 04:17:47 2016
@@ -521,6 +521,17 @@ public:
return CompactUnwindEncoding;
}
+
+ void processFixupValue(const MCAssembler &Asm, const MCAsmLayout &Layout,
+ const MCFixup &Fixup, const MCFragment *DF,
+ const MCValue &Target, uint64_t &Value,
+ bool &IsResolved) override {
+ // Try to get the encoded value for the fixup as-if we're mapping it into
+ // the instruction. This allows adjustFixupValue() to issue a diagnostic
+ // if the value is invalid.
+ if (IsResolved)
+ (void)adjustFixupValue(Fixup, Value, &Asm.getContext());
+ }
};
} // end anonymous namespace
Modified: llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp?rev=283862&r1=283861&r2=283862&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64MachObjectWriter.cpp Tue Oct 11 04:17:47 2016
@@ -75,7 +75,7 @@ bool AArch64MachObjectWriter::getAArch64
Log2Size = llvm::Log2_32(4);
switch (Sym->getKind()) {
default:
- llvm_unreachable("Unexpected symbol reference variant kind!");
+ return false;
case MCSymbolRefExpr::VK_PAGEOFF:
RelocType = unsigned(MachO::ARM64_RELOC_PAGEOFF12);
return true;
Modified: llvm/trunk/test/MC/AArch64/basic-a64-diagnostics.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/AArch64/basic-a64-diagnostics.s?rev=283862&r1=283861&r2=283862&view=diff
==============================================================================
--- llvm/trunk/test/MC/AArch64/basic-a64-diagnostics.s (original)
+++ llvm/trunk/test/MC/AArch64/basic-a64-diagnostics.s Tue Oct 11 04:17:47 2016
@@ -172,9 +172,14 @@
// A relocation should be provided for symbols
add x3, x9, #variable
+ add x3, x9, #variable-16
// CHECK-ERROR: error: expected compatible register, symbol or integer in range [0, 4095]
// CHECK-ERROR-NEXT: add x3, x9, #variable
// CHECK-ERROR-NEXT: ^
+// CHECK-ERROR-NEXT: error: expected compatible register, symbol or integer in range [0, 4095]
+// CHECK-ERROR-NEXT: add x3, x9, #variable-16
+// CHECK-ERROR-NEXT: ^
+
//------------------------------------------------------------------------------
Added: llvm/trunk/test/MC/AArch64/label-arithmetic-darwin.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/AArch64/label-arithmetic-darwin.s?rev=283862&view=auto
==============================================================================
--- llvm/trunk/test/MC/AArch64/label-arithmetic-darwin.s (added)
+++ llvm/trunk/test/MC/AArch64/label-arithmetic-darwin.s Tue Oct 11 04:17:47 2016
@@ -0,0 +1,61 @@
+// RUN: llvm-mc -triple aarch64-darwin -filetype=obj %s -o - | llvm-objdump -r -d - | FileCheck %s
+// RUN: llvm-mc -triple aarch64-ios -filetype=obj %s -o - | llvm-objdump -r -d - | FileCheck %s
+
+visible:
+ .space 8
+Lstart:
+ .space 8
+Lend:
+ adds w0, w1, #(Lend - Lstart)
+ adds x0, x1, #(Lend - Lstart)
+ add w0, w1, #(Lend - Lstart)
+ add x0, x1, #(Lend - Lstart)
+ cmp w0, #(Lend - Lstart)
+ cmp x0, #(Lend - Lstart)
+ sub w0, w1, #(Lend - Lstart)
+ sub x0, x1, #(Lend - Lstart)
+ // CHECK: adds w0, w1, #8
+ // CHECK: adds x0, x1, #8
+ // CHECK: add w0, w1, #8
+ // CHECK: add x0, x1, #8
+ // CHECK: cmp w0, #8
+ // CHECK: cmp x0, #8
+ // CHECK: sub w0, w1, #8
+ // CHECK: sub x0, x1, #8
+
+ add w0, w1, #(Lend - Lstart), lsl #12
+ cmp w0, #(Lend - Lstart), lsl #12
+ // CHECK: add w0, w1, #8, lsl #12
+ // CHECK: cmp w0, #8, lsl #12
+
+ add w0, w1, #((Lend - Lstart) >> 2)
+ cmp w0, #((Lend - Lstart) >> 2)
+ // CHECK: add w0, w1, #2
+ // CHECK: cmp w0, #2
+
+ add w0, w1, #(Lend - Lstart + 12)
+ cmp w0, #(Lend - Lstart + 12)
+ // CHECK: add w0, w1, #20
+ // CHECK: cmp w0, #20
+
+ add w0, w1, #(Lforward - Lend)
+ cmp w0, #(Lforward - Lend)
+ // CHECK: add w0, w1, #320
+ // CHECK: cmp w0, #320
+
+ add w0, w1, #(Lstart - visible)
+ cmp w0, #(Lstart - visible)
+ // CHECK: add w0, w1, #8
+ // CHECK: cmp w0, #8
+
+// Add some filler so we don't have to modify #(Lforward - Lend) if we add more
+// instructions above
+Lfiller:
+ .space 320 - (Lfiller - Lend)
+
+Lforward:
+ .space 4
+ add w0, w1, #(. - Lforward)
+ cmp w0, #(. - Lforward)
+ // CHECK: add w0, w1, #4
+ // CHECK: cmp w0, #8
Added: llvm/trunk/test/MC/AArch64/label-arithmetic-diags-darwin.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/AArch64/label-arithmetic-diags-darwin.s?rev=283862&view=auto
==============================================================================
--- llvm/trunk/test/MC/AArch64/label-arithmetic-diags-darwin.s (added)
+++ llvm/trunk/test/MC/AArch64/label-arithmetic-diags-darwin.s Tue Oct 11 04:17:47 2016
@@ -0,0 +1,68 @@
+// RUN: not llvm-mc -triple aarch64-darwin -filetype=obj %s -o /dev/null 2>&1 | FileCheck %s
+// RUN: not llvm-mc -triple aarch64-ios -filetype=obj %s -o /dev/null 2>&1 | FileCheck %s
+
+Lstart:
+ .space 8
+Lend:
+ add w0, w1, #(Lend - external)
+ cmp w0, #(Lend - external)
+ // CHECK: error: unknown AArch64 fixup kind!
+ // CHECK-NEXT: add w0, w1, #(Lend - external)
+ // CHECK-NEXT: ^
+ // CHECK: error: unknown AArch64 fixup kind!
+ // CHECK-NEXT: cmp w0, #(Lend - external)
+ // CHECK-NEXT: ^
+
+ add w0, w1, #(Lend - var at TLVPPAGEOFF)
+ cmp w0, #(Lend - var at TLVPPAGEOFF)
+ // CHECK: error: unknown AArch64 fixup kind!
+ // CHECK-NEXT: add w0, w1, #(Lend - var at TLVPPAGEOFF)
+ // CHECK-NEXT: ^
+ // CHECK: error: unknown AArch64 fixup kind!
+ // CHECK-NEXT: cmp w0, #(Lend - var at TLVPPAGEOFF)
+ // CHECK-NEXT: ^
+
+ add w0, w1, #(Lstart - Lend)
+ cmp w0, #(Lstart - Lend)
+ // CHECK: error: fixup value out of range
+ // CHECK-NEXT: add w0, w1, #(Lstart - Lend)
+ // CHECK-NEXT: ^
+ // CHECK: error: fixup value out of range
+ // CHECK-NEXT: cmp w0, #(Lstart - Lend)
+ // CHECK-NEXT: ^
+
+ .space 5000
+Lfar:
+ add w0, w1, #(Lfar - Lend)
+ cmp w0, #(Lfar - Lend)
+ // CHECK: error: fixup value out of range
+ // CHECK-NEXT: add w0, w1, #(Lfar - Lend)
+ // CHECK-NEXT: ^
+ // CHECK: error: fixup value out of range
+ // CHECK-NEXT: cmp w0, #(Lfar - Lend)
+ // CHECK-NEXT: ^
+
+Lprivate1:
+ .space 8
+notprivate:
+ .space 8
+Lprivate2:
+ add w0, w1, #(Lprivate2 - Lprivate1)
+ cmp w0, #(Lprivate2 - Lprivate1)
+ // CHECK: error: unknown AArch64 fixup kind!
+ // CHECK-NEXT: add w0, w1, #(Lprivate2 - Lprivate1)
+ // CHECK-NEXT: ^
+ // CHECK: error: unknown AArch64 fixup kind!
+ // CHECK-NEXT: cmp w0, #(Lprivate2 - Lprivate1)
+ // CHECK-NEXT: ^
+
+ .section __TEXT, sec_y, regular, pure_instructions
+Lend_across_sec:
+ add w0, w1, #(Lend_across_sec - Lprivate2)
+ cmp w0, #(Lend_across_sec - Lprivate2)
+ // CHECK: error: unknown AArch64 fixup kind!
+ // CHECK-NEXT: add w0, w1, #(Lend_across_sec - Lprivate2)
+ // CHECK-NEXT: ^
+ // CHECK: error: unknown AArch64 fixup kind!
+ // CHECK-NEXT: cmp w0, #(Lend_across_sec - Lprivate2)
+ // CHECK-NEXT: ^
Added: llvm/trunk/test/MC/AArch64/label-arithmetic-diags-elf.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/AArch64/label-arithmetic-diags-elf.s?rev=283862&view=auto
==============================================================================
--- llvm/trunk/test/MC/AArch64/label-arithmetic-diags-elf.s (added)
+++ llvm/trunk/test/MC/AArch64/label-arithmetic-diags-elf.s Tue Oct 11 04:17:47 2016
@@ -0,0 +1,71 @@
+// RUN: not llvm-mc -triple aarch64-elf -filetype=obj %s -o /dev/null 2>&1 | FileCheck %s
+
+ .section sec_x
+start:
+ .space 5000
+end:
+ add w0, w1, #(end - start)
+ cmp w0, #(end - start)
+ // CHECK: error: fixup value out of range
+ // CHECK-NEXT: add w0, w1, #(end - start)
+ // CHECK-NEXT: ^
+ // CHECK: error: fixup value out of range
+ // CHECK-NEXT: cmp w0, #(end - start)
+ // CHECK-NEXT: ^
+
+negative:
+ add w0, w1, #(end - negative)
+ cmp w0, #(end - negative)
+ // CHECK: error: fixup value out of range
+ // CHECK-NEXT: add w0, w1, #(end - negative)
+ // CHECK-NEXT: ^
+ // CHECK: error: fixup value out of range
+ // CHECK-NEXT: cmp w0, #(end - negative)
+ // CHECK-NEXT: ^
+
+ add w0, w1, #(end - external)
+ cmp w0, #(end - external)
+ // CHECK: error: symbol 'external' can not be undefined in a subtraction expression
+ // CHECK-NEXT: add w0, w1, #(end - external)
+ // CHECK-NEXT: ^
+ // CHECK: error: symbol 'external' can not be undefined in a subtraction expression
+ // CHECK-NEXT: cmp w0, #(end - external)
+ // CHECK-NEXT: ^
+
+ add w0, w1, #:lo12:external - end
+ cmp w0, #:lo12:external - end
+ // CHECK: error: Unsupported pc-relative fixup kind
+ // CHECK-NEXT: add w0, w1, #:lo12:external - end
+ // CHECK-NEXT: ^
+ // CHECK: error: Unsupported pc-relative fixup kind
+ // CHECK-NEXT: cmp w0, #:lo12:external - end
+ // CHECK-NEXT: ^
+
+ add w0, w1, #:got_lo12:external - end
+ cmp w0, #:got_lo12:external - end
+ // CHECK: error: Unsupported pc-relative fixup kind
+ // CHECK-NEXT: add w0, w1, #:got_lo12:external - end
+ // CHECK-NEXT: ^
+ // CHECK: error: Unsupported pc-relative fixup kind
+ // CHECK-NEXT: cmp w0, #:got_lo12:external - end
+ // CHECK-NEXT: ^
+
+ .section sec_y
+end_across_sec:
+ add w0, w1, #(end_across_sec - start)
+ cmp w0, #(end_across_sec - start)
+ // CHECK: error: Cannot represent a difference across sections
+ // CHECK-NEXT: add w0, w1, #(end_across_sec - start)
+ // CHECK-NEXT: ^
+ // CHECK: error: Cannot represent a difference across sections
+ // CHECK-NEXT: cmp w0, #(end_across_sec - start)
+ // CHECK-NEXT: ^
+
+ add w0, w1, #(sec_y - sec_x)
+ cmp w0, #(sec_y - sec_x)
+ // CHECK: error: symbol 'sec_x' can not be undefined in a subtraction expression
+ // CHECK-NEXT: add w0, w1, #(sec_y - sec_x)
+ // CHECK-NEXT: ^
+ // CHECK: error: symbol 'sec_x' can not be undefined in a subtraction expression
+ // CHECK-NEXT: cmp w0, #(sec_y - sec_x)
+ // CHECK-NEXT: ^
Added: llvm/trunk/test/MC/AArch64/label-arithmetic-elf.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/AArch64/label-arithmetic-elf.s?rev=283862&view=auto
==============================================================================
--- llvm/trunk/test/MC/AArch64/label-arithmetic-elf.s (added)
+++ llvm/trunk/test/MC/AArch64/label-arithmetic-elf.s Tue Oct 11 04:17:47 2016
@@ -0,0 +1,96 @@
+// RUN: llvm-mc -triple aarch64-elf -filetype=obj %s -o - | llvm-objdump -d - | FileCheck %s
+
+start:
+ .space 8
+end:
+ // CHECK-LABEL: end:
+
+ adds w0, w1, #(end - start)
+ adds x0, x1, #(end - start)
+ add w0, w1, #(end - start)
+ add x0, x1, #(end - start)
+ cmp w0, #(end - start)
+ cmp x0, #(end - start)
+ sub w0, w1, #(end - start)
+ sub x0, x1, #(end - start)
+ // CHECK: adds w0, w1, #8
+ // CHECK: adds x0, x1, #8
+ // CHECK: add w0, w1, #8
+ // CHECK: add x0, x1, #8
+ // CHECK: cmp w0, #8
+ // CHECK: cmp x0, #8
+ // CHECK: sub w0, w1, #8
+ // CHECK: sub x0, x1, #8
+
+ add w0, w1, #(end - start), lsl #12
+ cmp w0, #(end - start), lsl #12
+ // CHECK: add w0, w1, #8, lsl #12
+ // CHECK: cmp w0, #8, lsl #12
+
+ add w0, w1, #((end - start) >> 2)
+ cmp w0, #((end - start) >> 2)
+ // CHECK: add w0, w1, #2
+ // CHECK: cmp w0, #2
+
+ add w0, w1, #(end - start + 12)
+ cmp w0, #(end - start + 12)
+ // CHECK: add w0, w1, #20
+ // CHECK: cmp w0, #20
+
+ add w0, w1, #(forward - end)
+ cmp w0, #(forward - end)
+ // CHECK: add w0, w1, #320
+ // CHECK: cmp w0, #320
+
+// Add some filler so we don't have to modify #(forward - end) if we add more
+// instructions above
+.Lfiller:
+ .space 320 - (.Lfiller - end)
+
+forward:
+ .space 8
+
+.Lstart:
+ .space 8
+.Lend:
+ add w0, w1, #(.Lend - .Lstart)
+ cmp w0, #(.Lend - .Lstart)
+ // CHECK: add w0, w1, #8
+ // CHECK: cmp w0, #8
+
+.Lprivate1:
+ .space 8
+notprivate:
+ .space 8
+.Lprivate2:
+ add w0, w1, #(.Lprivate2 - .Lprivate1)
+ cmp w0, #(.Lprivate2 - .Lprivate1)
+ // CHECK: add w0, w1, #16
+ // CHECK: cmp w0, #16
+
+ .type foo, @function
+foo:
+ // CHECK-LABEL: foo:
+
+ add w0, w1, #(foo - .Lprivate2)
+ cmp w0, #(foo - .Lprivate2)
+ // CHECK: add w0, w1, #8
+ // CHECK: cmp w0, #8
+
+ ret
+
+ .type goo, @function
+goo:
+ // CHECK-LABEL: goo:
+
+ add w0, w1, #(goo - foo)
+ cmp w0, #(goo - foo)
+ // CHECK: add w0, w1, #12
+ // CHECK: cmp w0, #12
+
+ add w0, w1, #(. - goo)
+ cmp w0, #(. - goo)
+ // CHECK: add w0, w1, #8
+ // CHECK: cmp w0, #12
+
+ ret
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