Fix block label printing in precise-output tests

cranelift/codegen/src/machinst/mod.rs

@@ -354,49 +354,66 @@ impl<T: CompilePhase> CompiledCodeBase<T> {
 
         let relocs = self.buffer.relocs();
         let traps = self.buffer.traps();
-        let labels = self.bb_starts.as_slice();
 
-        let insns = cs.disasm_all(self.buffer.data(), 0x0).map_err(map_caperr)?;
-        for i in insns.iter() {
-            if let Some((n, off)) = labels
-                .iter()
-                .copied()
-                .enumerate()
-                .find(|(_, val)| *val == i.address() as u32)
-            {
-                writeln!(buf, "block{}: ; offset 0x{:x}", n, off)?;
+        // Normalize the block starts to include an initial block of offset 0.
+        let block_starts = if let Some(start) = self.bb_starts.first() {
+            let mut starts = Vec::new();
+            if *start != 0 {
+                starts.push(0);
             }
+            starts.extend_from_slice(&self.bb_starts);
+            starts
+        } else {
+            vec![0]
+        };
 
-            write!(buf, "  ")?;
-
-            let op_str = i.op_str().unwrap_or("");
-            if let Some(s) = i.mnemonic() {
-                write!(buf, "{}", s)?;
-                if !op_str.is_empty() {
-                    write!(buf, " ")?;
+        // Iterate over block regions, to ensure that we always produce block labels
+        let end = self.buffer.data().len();
+        for (n, start) in block_starts.iter().enumerate() {
+            let start = *start as usize;
+            let end = if let Some(next) = block_starts.get(n + 1) {
+                *next as usize
+            } else {
+                end
+            };
+
+            writeln!(buf, "block{}: ; offset 0x{:x}", n, start)?;
+
+            let insns = cs
+                .disasm_all(&self.buffer.data()[start..end], start as u64)
+                .map_err(map_caperr)?;
+            for i in insns.iter() {
+                write!(buf, "  ")?;
+
+                let op_str = i.op_str().unwrap_or("");
+                if let Some(s) = i.mnemonic() {
+                    write!(buf, "{}", s)?;
+                    if !op_str.is_empty() {
+                        write!(buf, " ")?;
+                    }
                 }
-            }
 
-            write!(buf, "{}", op_str)?;
+                write!(buf, "{}", op_str)?;
 
-            let end = i.address() + i.bytes().len() as u64;
-            let contains = |off| i.address() <= off && off < end;
+                let end = i.address() + i.bytes().len() as u64;
+                let contains = |off| i.address() <= off && off < end;
 
-            if let Some(reloc) = relocs.iter().find(|reloc| contains(reloc.offset as u64)) {
-                write!(
-                    buf,
-                    " ; reloc_external {} {} {}",
-                    reloc.kind,
-                    reloc.name.display(params),
-                    reloc.addend,
-                )?;
-            }
+                if let Some(reloc) = relocs.iter().find(|reloc| contains(reloc.offset as u64)) {
+                    write!(
+                        buf,
+                        " ; reloc_external {} {} {}",
+                        reloc.kind,
+                        reloc.name.display(params),
+                        reloc.addend,
+                    )?;
+                }
 
-            if let Some(trap) = traps.iter().find(|trap| contains(trap.offset as u64)) {
-                write!(buf, " ; trap: {}", trap.code)?;
-            }
+                if let Some(trap) = traps.iter().find(|trap| contains(trap.offset as u64)) {
+                    write!(buf, " ; trap: {}", trap.code)?;
+                }
 
-            writeln!(buf)?;
+                writeln!(buf)?;
+            }
         }
 
         return Ok(buf);

cranelift/filetests/filetests/egraph/multivalue.clif

@@ -26,9 +26,10 @@ function u0:359(i64) -> i8, i8 system_v {
 ;   ret
 ; 
 ; Disassembled:
+; block0: ; offset 0x0
 ;   pushq %rbp
 ;   movq %rsp, %rbp
-; block0: ; offset 0x4
+; block1: ; offset 0x4
 ;   callq 9 ; reloc_external CallPCRel4 u0:521 -4
 ;   movq %rbp, %rsp
 ;   popq %rbp

cranelift/filetests/filetests/egraph/not_a_load.clif

@@ -24,9 +24,10 @@ function u0:1302(i64) -> i64 system_v {
 ;   ret
 ; 
 ; Disassembled:
+; block0: ; offset 0x0
 ;   pushq %rbp
 ;   movq %rsp, %rbp
-; block0: ; offset 0x4
+; block1: ; offset 0x4
 ;   movq (%rdi), %rax ; trap: heap_oob
 ;   movq %rax, %rcx
 ;   addq %rdi, %rcx

cranelift/filetests/filetests/isa/aarch64/atomic-cas.clif

@@ -30,12 +30,13 @@ block0(v0: i64, v1: i32, v2: i32):
 ;   ret
 ; 
 ; Disassembled:
+; block0: ; offset 0x0
 ;   stp x29, x30, [sp, #-0x10]!
 ;   mov x29, sp
 ;   str x28, [sp, #-0x10]!
 ;   stp x26, x27, [sp, #-0x10]!
 ;   stp x24, x25, [sp, #-0x10]!
-; block0: ; offset 0x14
+; block1: ; offset 0x14
 ;   mov x25, x0
 ;   mov x26, x1
 ;   mov x28, x2

cranelift/filetests/filetests/isa/aarch64/atomic-rmw-lse.clif

@@ -232,12 +232,13 @@ block0(v0: i64, v1: i64):
 ;   ret
 ; 
 ; Disassembled:
+; block0: ; offset 0x0
 ;   stp x29, x30, [sp, #-0x10]!
 ;   mov x29, sp
 ;   str x28, [sp, #-0x10]!
 ;   stp x26, x27, [sp, #-0x10]!
 ;   stp x24, x25, [sp, #-0x10]!
-; block0: ; offset 0x14
+; block1: ; offset 0x14
 ;   mov x25, x0
 ;   mov x26, x1
 ;   ldaxr x27, [x25]
@@ -274,12 +275,13 @@ block0(v0: i64, v1: i32):
 ;   ret
 ; 
 ; Disassembled:
+; block0: ; offset 0x0
 ;   stp x29, x30, [sp, #-0x10]!
 ;   mov x29, sp
 ;   str x28, [sp, #-0x10]!
 ;   stp x26, x27, [sp, #-0x10]!
 ;   stp x24, x25, [sp, #-0x10]!
-; block0: ; offset 0x14
+; block1: ; offset 0x14
 ;   mov x25, x0
 ;   mov x26, x1
 ;   ldaxr w27, [x25]
@@ -316,12 +318,13 @@ block0(v0: i64, v1: i16):
 ;   ret
 ; 
 ; Disassembled:
+; block0: ; offset 0x0
 ;   stp x29, x30, [sp, #-0x10]!
 ;   mov x29, sp
 ;   str x28, [sp, #-0x10]!
 ;   stp x26, x27, [sp, #-0x10]!
 ;   stp x24, x25, [sp, #-0x10]!
-; block0: ; offset 0x14
+; block1: ; offset 0x14
 ;   mov x25, x0
 ;   mov x26, x1
 ;   ldaxrh w27, [x25]
@@ -358,12 +361,13 @@ block0(v0: i64, v1: i8):
 ;   ret
 ; 
 ; Disassembled:
+; block0: ; offset 0x0
 ;   stp x29, x30, [sp, #-0x10]!
 ;   mov x29, sp
 ;   str x28, [sp, #-0x10]!
 ;   stp x26, x27, [sp, #-0x10]!
 ;   stp x24, x25, [sp, #-0x10]!
-; block0: ; offset 0x14
+; block1: ; offset 0x14
 ;   mov x25, x0
 ;   mov x26, x1
 ;   ldaxrb w27, [x25]