Kyle Huey 652b502d9c Reorder stack spills so that constants come later. ... Currently constants are "pulled forward" and have their stack spills emitted first. This confuses LLVM as to where to place breakpoints at function entry, and results in argument values being wrong in the debugger. It's straightforward to avoid emitting the stack spills for constants until arguments/etc have been introduced in debug_introduce_locals, so do that. Example LLVM IR (irrelevant IR elided): Before: define internal void @_ZN11rust_1289457binding17h2c78f956ba4bd2c3E(i64 %a, i64 %b, double %c) unnamed_addr #0 !dbg !178 { start: %c.dbg.spill = alloca [8 x i8], align 8 %b.dbg.spill = alloca [8 x i8], align 8 %a.dbg.spill = alloca [8 x i8], align 8 %x.dbg.spill = alloca [4 x i8], align 4 store i32 0, ptr %x.dbg.spill, align 4, !dbg !192 ; LLVM places breakpoint here. #dbg_declare(ptr %x.dbg.spill, !190, !DIExpression(), !192) store i64 %a, ptr %a.dbg.spill, align 8 #dbg_declare(ptr %a.dbg.spill, !187, !DIExpression(), !193) store i64 %b, ptr %b.dbg.spill, align 8 #dbg_declare(ptr %b.dbg.spill, !188, !DIExpression(), !194) store double %c, ptr %c.dbg.spill, align 8 #dbg_declare(ptr %c.dbg.spill, !189, !DIExpression(), !195) ret void, !dbg !196 } After: define internal void @_ZN11rust_1289457binding17h2c78f956ba4bd2c3E(i64 %a, i64 %b, double %c) unnamed_addr #0 !dbg !178 { start: %x.dbg.spill = alloca [4 x i8], align 4 %c.dbg.spill = alloca [8 x i8], align 8 %b.dbg.spill = alloca [8 x i8], align 8 %a.dbg.spill = alloca [8 x i8], align 8 store i64 %a, ptr %a.dbg.spill, align 8 #dbg_declare(ptr %a.dbg.spill, !187, !DIExpression(), !192) store i64 %b, ptr %b.dbg.spill, align 8 #dbg_declare(ptr %b.dbg.spill, !188, !DIExpression(), !193) store double %c, ptr %c.dbg.spill, align 8 #dbg_declare(ptr %c.dbg.spill, !189, !DIExpression(), !194) store i32 0, ptr %x.dbg.spill, align 4, !dbg !195 ; LLVM places breakpoint here. #dbg_declare(ptr %x.dbg.spill, !190, !DIExpression(), !195) ret void, !dbg !196 } Note in particular the position of the "LLVM places breakpoint here" comment relative to the stack spills for the function arguments. LLVM assumes that the first instruction with with a debug location is the end of the prologue. As LLVM does not currently offer front ends any direct control over the placement of the prologue end reordering the IR is the only mechanism available to fix argument values at function entry in the presence of MIR optimizations like SingleUseConsts. Fixes #128945		2024-09-17 16:45:26 -07:00
..
assembly	Ignore reduce-fadd-unordered on SGX platform	2024-09-16 16:54:48 +02:00
auxiliary
codegen	Update try_question_mark_nop.rs test	2024-09-14 13:30:36 +08:00
codegen-units
coverage	coverage: Extract executor::block_on from several async coverage tests	2024-09-10 16:08:36 +10:00
coverage-run-rustdoc
crashes	Auto merge of #129970 - lukas-code:LayoutCalculator, r=compiler-errors	2024-09-17 01:17:48 +00:00
debuginfo	Reorder stack spills so that constants come later.	2024-09-17 16:45:26 -07:00
incremental	simd_shuffle: require index argument to be a vector	2024-09-14 14:43:24 +02:00
mir-opt	Remove semi-nondeterminism of DefPathHash ordering from inliner	2024-09-16 21:41:15 -04:00
pretty	Use doc(hidden) instead of allow(missing_docs) in the test harness	2024-09-11 12:14:35 +02:00
run-make	tests/run-make: update for symlink helper changes	2024-09-16 21:31:41 +08:00
run-pass-valgrind
rustdoc	rustdoc: rename issue-\d+.rs tests to have meaningful names	2024-09-12 13:47:51 -07:00
rustdoc-gui	Rollup merge of #129796 - GuillaumeGomez:unify-code-examples, r=notriddle	2024-09-05 18:58:56 +02:00
rustdoc-js	rustdoc-search: allow trailing Foo -> arg search	2024-09-05 17:58:05 -07:00
rustdoc-js-std	rustdoc-search: allow trailing Foo -> arg search	2024-09-05 17:58:05 -07:00
rustdoc-json	rustdoc: normalise type/field names in rustdoc-json-types/jsondoclint	2024-09-01 23:58:08 +03:00
rustdoc-ui	rustdoc: re-bless stderrs after renaming the test case	2024-09-12 13:48:51 -07:00
ui	Rollup merge of #130440 - compiler-errors:rpitit-opaque-hidden, r=jieyouxu	2024-09-17 17:28:34 +02:00
ui-fulldeps	Auto merge of #130483 - matthiaskrgr:rollup-q1r0g0y, r=matthiaskrgr	2024-09-17 19:37:03 +00:00
COMPILER_TESTS.md