Rollup merge of #125108 - Zalathar:info-bitmap-bytes, r=nnethercote

coverage: `CoverageIdsInfo::mcdc_bitmap_bytes` is never needed

This code for recalculating `mcdc_bitmap_bytes` in a query doesn't provide any benefit, because its result won't have changed from the value in `FunctionCoverageInfo` that was computed during the MIR instrumentation pass.

Extracted from #124571, to avoid having this held up by unrelated issues with condition count checks.

`@rustbot` label +A-code-coverage

2 files changed, 0 insertions, 10 deletions

diff --git a/compiler/rustc_middle/src/mir/coverage.rs b/compiler/rustc_middle/src/mir/coverage.rs
index 477303e2434..7f9a5a366d7 100644
--- a/compiler/rustc_middle/src/mir/coverage.rs
+++ b/compiler/rustc_middle/src/mir/coverage.rs
@@ -129,17 +129,11 @@ pub enum CoverageKind {
     /// Marks the point in MIR control flow represented by a evaluated condition.
     ///
     /// This is eventually lowered to `llvm.instrprof.mcdc.condbitmap.update` in LLVM IR.
-    ///
-    /// If this statement does not survive MIR optimizations, the condition would never be
-    /// taken as evaluated.
     CondBitmapUpdate { id: ConditionId, value: bool, decision_depth: u16 },
 
     /// Marks the point in MIR control flow represented by a evaluated decision.
     ///
     /// This is eventually lowered to `llvm.instrprof.mcdc.tvbitmap.update` in LLVM IR.
-    ///
-    /// If this statement does not survive MIR optimizations, the decision would never be
-    /// taken as evaluated.
     TestVectorBitmapUpdate { bitmap_idx: u32, decision_depth: u16 },
 }
 
diff --git a/compiler/rustc_middle/src/mir/query.rs b/compiler/rustc_middle/src/mir/query.rs
index 9a7af6135e4..9d70231be3b 100644
--- a/compiler/rustc_middle/src/mir/query.rs
+++ b/compiler/rustc_middle/src/mir/query.rs
@@ -362,8 +362,4 @@ pub struct CoverageIdsInfo {
     /// InstrumentCoverage MIR pass, if the highest-numbered counter increments
     /// were removed by MIR optimizations.
     pub max_counter_id: mir::coverage::CounterId,
-
-    /// Coverage codegen for mcdc needs to know the size of the global bitmap so that it can
-    /// set the `bytemap-bytes` argument of the `llvm.instrprof.mcdc.tvbitmap.update` intrinsic.
-    pub mcdc_bitmap_bytes: u32,
 }