Remove some minor checks for LLVM < 12

Author: cuviper

compiler/rustc_codegen_llvm/src/abi.rs

@@ -1,7 +1,6 @@
 use crate::builder::Builder;
 use crate::context::CodegenCx;
 use crate::llvm::{self, AttributePlace};
-use crate::llvm_util;
 use crate::type_::Type;
 use crate::type_of::LayoutLlvmExt;
 use crate::value::Value;
@@ -53,15 +52,10 @@ pub trait ArgAttributesExt {
 }
 
 fn should_use_mutable_noalias(cx: &CodegenCx<'_, '_>) -> bool {
-    // LLVM prior to version 12 has known miscompiles in the presence of
-    // noalias attributes (see #54878). Only enable mutable noalias by
-    // default for versions we believe to be safe.
-    cx.tcx
-        .sess
-        .opts
-        .debugging_opts
-        .mutable_noalias
-        .unwrap_or_else(|| llvm_util::get_version() >= (12, 0, 0))
+    // LLVM prior to version 12 had known miscompiles in the presence of
+    // noalias attributes (see #54878), but we don't support earlier
+    // versions at all anymore. We now enable mutable noalias by default.
+    cx.tcx.sess.opts.debugging_opts.mutable_noalias.unwrap_or(true)
 }
 
 impl ArgAttributesExt for ArgAttributes {

compiler/rustc_codegen_llvm/src/builder.rs

@@ -731,7 +731,7 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
     }
 
     fn fptoui_sat(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> Option<&'ll Value> {
-        if llvm_util::get_version() >= (12, 0, 0) && !self.fptoint_sat_broken_in_llvm() {
+        if !self.fptoint_sat_broken_in_llvm() {
             let src_ty = self.cx.val_ty(val);
             let float_width = self.cx.float_width(src_ty);
             let int_width = self.cx.int_width(dest_ty);
@@ -743,7 +743,7 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
     }
 
     fn fptosi_sat(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> Option<&'ll Value> {
-        if llvm_util::get_version() >= (12, 0, 0) && !self.fptoint_sat_broken_in_llvm() {
+        if !self.fptoint_sat_broken_in_llvm() {
             let src_ty = self.cx.val_ty(val);
             let float_width = self.cx.float_width(src_ty);
             let int_width = self.cx.int_width(dest_ty);

compiler/rustc_codegen_llvm/src/context.rs

@@ -134,9 +134,6 @@ pub unsafe fn create_module(
     let llmod = llvm::LLVMModuleCreateWithNameInContext(mod_name.as_ptr(), llcx);
 
     let mut target_data_layout = sess.target.data_layout.clone();
-    if llvm_util::get_version() < (12, 0, 0) && sess.target.arch == "powerpc64" {
-        target_data_layout = target_data_layout.replace("-v256:256:256-v512:512:512", "");
-    }
     if llvm_util::get_version() < (13, 0, 0) {
         if sess.target.arch == "powerpc64" {
             target_data_layout = target_data_layout.replace("-S128", "");