From 0e7a9ab98f135afc8fd0726b9272141a3f30660f Mon Sep 17 00:00:00 2001 From: Joseph Ferano Date: Fri, 25 Sep 2026 10:21:28 +0700 Subject: [PATCH] The x86 survey is to compare against LLVM at -O0 only --- TODO.org | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/TODO.org b/TODO.org index 73efe62b..f83e2878 100644 --- a/TODO.org +++ b/TODO.org @@ -1056,7 +1056,8 @@ Every program in the corpus that compiles, has a =main= and terminates agrees wi the LLVM build down to stderr. =docs/BUILT.md=, "The hand-written x86 backend, and the four measurements behind it", is the account. -** TODO Nothing pins the LLVM side at -O0 when the two backends are compared +** NEXT Nothing pins the LLVM side at -O0 when the two backends are compared +Decided 2026-09-25: the x86 parity survey compares against LLVM at -O0 only; -O2 is never its target. The acceptance suite's paired -O2/-O0 rows stay, being the check for undefined behaviour in emitted IR, which is a different question. The survey builds both sides at the default =-O2=, so a construct LLVM folds is compared as a constant rather than as a lowering. That is how the float =%= gap survived. Two things would close it: an =-O0= pass of the sweep, and something