From a76f7a2972f35bae4f6ef10a0f22b48c7c323476 Mon Sep 17 00:00:00 2001 From: Tsukasa OI Date: Fri, 19 Sep 2025 04:58:26 +0000 Subject: [PATCH 1/3] rustc_codegen_llvm: Split "Fixed in LLVM 20" cases ... in `update_target_reliable_float_cfg`, based on the actual changes. The AArch64 issue is fixed on LLVM 20.1.1 while the MIPS issue is fixed on LLVM 20.1.0 (the first LLVM 20 release). This commit distinguishes two separate cases. --- compiler/rustc_codegen_llvm/src/llvm_util.rs | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs index 8461c8b03d5a4..6e159de637367 100644 --- a/compiler/rustc_codegen_llvm/src/llvm_util.rs +++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs @@ -335,11 +335,12 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) { let target_abi = sess.target.options.abi.as_ref(); let target_pointer_width = sess.target.pointer_width; let version = get_version(); + let lt_20_1_0 = version < (20, 1, 0); let lt_20_1_1 = version < (20, 1, 1); let lt_21_0_0 = version < (21, 0, 0); cfg.has_reliable_f16 = match (target_arch, target_os) { - // LLVM crash without neon (fixed in llvm20) + // LLVM crash without neon (fixed in LLVM 20.1.1) ("aarch64", _) if !cfg.target_features.iter().any(|f| f.as_str() == "neon") && lt_20_1_1 => { @@ -367,7 +368,7 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) { // Unsupported ("arm64ec", _) => false, // Selection bug (fixed in llvm20) - ("mips64" | "mips64r6", _) if lt_20_1_1 => false, + ("mips64" | "mips64r6", _) if lt_20_1_0 => false, // Selection bug . This issue is closed // but basic math still does not work. ("nvptx64", _) => false, From 7d3f54482ac9c12f3ee1cca75e385cd217bba90d Mon Sep 17 00:00:00 2001 From: Tsukasa OI Date: Fri, 19 Sep 2025 04:14:10 +0000 Subject: [PATCH 2/3] rustc_codegen_llvm: Simplify `update_target_reliable_float_cfg` This commit simplifies floating type handling through `update_target_reliable_float_cfg` based on several facts: 1. Major changes in behavior normally occurs only on the major LLVM upgrade. 2. The first release of LLVM 20.x.x is 20.1.0. Due to the first fact, we can normally ignore minor and patch releases of LLVM and we can remove obscure variables like `lt_xx_x_x` (still, there is a case where checking for patch version is required). The second fact is missed when the minimum LLVM version is raised to LLVM 20 and one "fixed in LLVM 20" case can be safely removed. --- compiler/rustc_codegen_llvm/src/llvm_util.rs | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs index 6e159de637367..10edb68971802 100644 --- a/compiler/rustc_codegen_llvm/src/llvm_util.rs +++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs @@ -335,26 +335,25 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) { let target_abi = sess.target.options.abi.as_ref(); let target_pointer_width = sess.target.pointer_width; let version = get_version(); - let lt_20_1_0 = version < (20, 1, 0); - let lt_20_1_1 = version < (20, 1, 1); - let lt_21_0_0 = version < (21, 0, 0); + let (major, _, _) = version; cfg.has_reliable_f16 = match (target_arch, target_os) { // LLVM crash without neon (fixed in LLVM 20.1.1) ("aarch64", _) - if !cfg.target_features.iter().any(|f| f.as_str() == "neon") && lt_20_1_1 => + if !cfg.target_features.iter().any(|f| f.as_str() == "neon") + && version < (20, 1, 1) => { false } // Unsupported ("arm64ec", _) => false, // Selection failure (fixed in llvm21) - ("s390x", _) if lt_21_0_0 => false, + ("s390x", _) if major < 21 => false, // MinGW ABI bugs ("x86_64", "windows") if target_env == "gnu" && target_abi != "llvm" => false, // Infinite recursion ("csky", _) => false, - ("hexagon", _) if lt_21_0_0 => false, // (fixed in llvm21) + ("hexagon", _) if major < 21 => false, // (fixed in llvm21) ("powerpc" | "powerpc64", _) => false, ("sparc" | "sparc64", _) => false, ("wasm32" | "wasm64", _) => false, @@ -367,8 +366,6 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) { cfg.has_reliable_f128 = match (target_arch, target_os) { // Unsupported ("arm64ec", _) => false, - // Selection bug (fixed in llvm20) - ("mips64" | "mips64r6", _) if lt_20_1_0 => false, // Selection bug . This issue is closed // but basic math still does not work. ("nvptx64", _) => false, @@ -381,7 +378,7 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) { ("sparc", _) => false, // Stack alignment bug . NB: tests may // not fail if our compiler-builtins is linked. (fixed in llvm21) - ("x86", _) if lt_21_0_0 => false, + ("x86", _) if major < 21 => false, // MinGW ABI bugs ("x86_64", "windows") if target_env == "gnu" && target_abi != "llvm" => false, // There are no known problems on other platforms, so the only requirement is that symbols From de33db287550e315ae34f7e6a0b98cbed933f25b Mon Sep 17 00:00:00 2001 From: Tsukasa OI Date: Fri, 19 Sep 2025 04:14:10 +0000 Subject: [PATCH 3/3] rustc_codegen_llvm: Reorder by arch in `update_target_reliable_float_cfg` This commit reorders certain match clauses in `update_target_reliable_float_cfg` by the architecture when there's no problems reordering it. --- compiler/rustc_codegen_llvm/src/llvm_util.rs | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs index 10edb68971802..25a123b10f5de 100644 --- a/compiler/rustc_codegen_llvm/src/llvm_util.rs +++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs @@ -364,13 +364,13 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) { }; cfg.has_reliable_f128 = match (target_arch, target_os) { + // Unsupported https://github.com/llvm/llvm-project/issues/121122 + ("amdgpu", _) => false, // Unsupported ("arm64ec", _) => false, // Selection bug . This issue is closed // but basic math still does not work. ("nvptx64", _) => false, - // Unsupported https://github.com/llvm/llvm-project/issues/121122 - ("amdgpu", _) => false, // ABI bugs et al. (full // list at ) ("powerpc" | "powerpc64", _) => false,