[llvm] [feature][riscv] handle target address calculation in llvm-objdump disassembly for riscv (PR #144620)

[Sam Elliott via llvm-commits]

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@@ -0,0 +1,107 @@
+# RUN: %clang --target=fuchsia-elf-riscv64 -march=rv64gc_zcb %s -nostdlib -o %t
+# RUN: llvm-objdump -d %t | FileCheck %s
+
+# CHECK: 0000000000001000 <_start>:
+# CHECK-NEXT:     1000: 00001517     	auipc	a0, 0x1
+# CHECK-NEXT:     1004: 00450513     	addi	a0, a0, 0x4 <target>
+# CHECK-NEXT:     1008: 00001517     	auipc	a0, 0x1
+# CHECK-NEXT:     100c: 1571         	addi	a0, a0, -0x4 <target>
+# CHECK-NEXT:     100e: 6509         	lui	a0, 0x2
+# CHECK-NEXT:     1010: 0045059b     	addiw	a1, a0, 0x4 <target>
+# CHECK-NEXT:     1014: 6509         	lui	a0, 0x2
+# CHECK-NEXT:     1016: 2511         	addiw	a0, a0, 0x4 <target>
+# CHECK-NEXT:     1018: 00102537     	lui	a0, 0x102
+# CHECK-NEXT:     101c: c50c         	sw	a1, 0x8(a0) <far_target>
+# CHECK-NEXT:     101e: 00102537     	lui	a0, 0x102
+# CHECK-NEXT:     1022: 4508         	lw	a0, 0x8(a0) <far_target>
+# CHECK-NEXT:     1024: 6509         	lui	a0, 0x2
+# CHECK-NEXT:     1026: 6585         	lui	a1, 0x1
+# CHECK-NEXT:     1028: 0306         	slli	t1, t1, 0x1
+# CHECK-NEXT:     102a: 0511         	addi	a0, a0, 0x4 <target>
+# CHECK-NEXT:     102c: 0505         	addi	a0, a0, 0x1
+# CHECK-NEXT:     102e: 00200037     	lui	zero, 0x200
+# CHECK-NEXT:     1032: 00a02423     	sw	a0, 0x8(zero)
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lenary wrote:

I'm not sure how easy this would be to test, but if you have a symbol at address 0x8, then this should probably say `sw a0, 0x8(x0) <symbol>`

I agree that the `lui`/`auipc` should not be updating the tracked value of `x0` (from the comment above), but we should entertain the possibility of an embedded system using addresses in the first/last page.

https://github.com/llvm/llvm-project/pull/144620