Rollup merge of #113603 - workingjubilee:test-for-98016, r=oli-obk

Test simd-wide-sum for codegen error

This adds the necessary test infrastructure to "build-pass" codegen tests, for the purpose of doing that for a single revision of a codegen test. When mir-opts are tested, the output may vary from the usual, and maybe for positive reasons... but we don't necessarily want to output such bad LLVMIR that LLVM starts crashing on it.

Currently when enabling MIR opts at higher levels this LLVMIR is still emitted, but it was previously disabled for getting in mir-opt's way and as this new revision without `// [mir-opt3]build-pass` would make it more likely to, I would like to not see the testing for the actual results regress again just because it was bundled with an ICE check as well.

This fixes #98016

Author: matthiaskrgr

src/tools/compiletest/src/header.rs

@@ -541,16 +541,15 @@ impl TestProps {
     }
 
     fn update_pass_mode(&mut self, ln: &str, revision: Option<&str>, config: &Config) {
-        let check_no_run = |s| {
-            if config.mode != Mode::Ui && config.mode != Mode::Incremental {
-                panic!("`{}` header is only supported in UI and incremental tests", s);
-            }
-            if config.mode == Mode::Incremental
-                && !revision.map_or(false, |r| r.starts_with("cfail"))
-                && !self.revisions.iter().all(|r| r.starts_with("cfail"))
-            {
-                panic!("`{}` header is only supported in `cfail` incremental tests", s);
+        let check_no_run = |s| match (config.mode, s) {
+            (Mode::Ui, _) => (),
+            (Mode::Codegen, "build-pass") => (),
+            (Mode::Incremental, _) => {
+                if revision.is_some() && !self.revisions.iter().all(|r| r.starts_with("cfail")) {
+                    panic!("`{s}` header is only supported in `cfail` incremental tests")
+                }
             }
+            (mode, _) => panic!("`{s}` header is not supported in `{mode}` tests"),
         };
         let pass_mode = if config.parse_name_directive(ln, "check-pass") {
             check_no_run("check-pass");
@@ -559,9 +558,7 @@ impl TestProps {
             check_no_run("build-pass");
             Some(PassMode::Build)
         } else if config.parse_name_directive(ln, "run-pass") {
-            if config.mode != Mode::Ui {
-                panic!("`run-pass` header is only supported in UI tests")
-            }
+            check_no_run("run-pass");
             Some(PassMode::Run)
         } else {
             None

src/tools/compiletest/src/runtest.rs

@@ -2752,6 +2752,10 @@ impl<'test> TestCx<'test> {
             self.fatal_proc_rec("compilation failed!", &proc_res);
         }
 
+        if let Some(PassMode::Build) = self.pass_mode() {
+            return;
+        }
+
         let output_path = self.output_base_name().with_extension("ll");
         let proc_res = self.verify_with_filecheck(&output_path);
         if !proc_res.status.success() {

tests/codegen/simd-wide-sum.rs

@@ -1,6 +1,11 @@
+// revisions: llvm mir-opt3
 // compile-flags: -C opt-level=3 -Z merge-functions=disabled --edition=2021
 // only-x86_64
 // ignore-debug: the debug assertions get in the way
+// [mir-opt3]compile-flags: -Zmir-opt-level=3
+// [mir-opt3]build-pass
+
+// mir-opt3 is a regression test for https://github.com/rust-lang/rust/issues/98016
 
 #![crate_type = "lib"]
 #![feature(portable_simd)]
@@ -47,9 +52,8 @@ pub fn wider_reduce_iter(x: Simd<u8, N>) -> u16 {
 #[no_mangle]
 // CHECK-LABEL: @wider_reduce_into_iter
 pub fn wider_reduce_into_iter(x: Simd<u8, N>) -> u16 {
-    // FIXME MIR inlining messes up LLVM optimizations.
-    // WOULD-CHECK: zext <8 x i8>
-    // WOULD-CHECK-SAME: to <8 x i16>
-    // WOULD-CHECK: call i16 @llvm.vector.reduce.add.v8i16(<8 x i16>
+    // CHECK: zext <8 x i8>
+    // CHECK-SAME: to <8 x i16>
+    // CHECK: call i16 @llvm.vector.reduce.add.v8i16(<8 x i16>
     x.to_array().into_iter().map(u16::from).sum()
 }