Rollup merge of #100460 - cuviper:drop-llvm-12, r=nagisa

Update the minimum external LLVM to 13

With this change, we'll have stable support for LLVM 13 through 15 (pending release).
For reference, the previous increase to LLVM 12 was #90175.

r? `@nagisa`

1 files changed, 25 insertions, 54 deletions

diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs
index d3096c73a8a..073feecb164 100644
--- a/compiler/rustc_codegen_llvm/src/builder.rs
+++ b/compiler/rustc_codegen_llvm/src/builder.rs
@@ -3,7 +3,6 @@ use crate::common::Funclet;
 use crate::context::CodegenCx;
 use crate::llvm::{self, BasicBlock, False};
 use crate::llvm::{AtomicOrdering, AtomicRmwBinOp, SynchronizationScope};
-use crate::llvm_util;
 use crate::type_::Type;
 use crate::type_of::LayoutLlvmExt;
 use crate::value::Value;
@@ -1038,25 +1037,11 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         dst: &'ll Value,
         cmp: &'ll Value,
         src: &'ll Value,
-        mut order: rustc_codegen_ssa::common::AtomicOrdering,
+        order: rustc_codegen_ssa::common::AtomicOrdering,
         failure_order: rustc_codegen_ssa::common::AtomicOrdering,
         weak: bool,
     ) -> &'ll Value {
         let weak = if weak { llvm::True } else { llvm::False };
-        if llvm_util::get_version() < (13, 0, 0) {
-            use rustc_codegen_ssa::common::AtomicOrdering::*;
-            // Older llvm has the pre-C++17 restriction on
-            // success and failure memory ordering,
-            // requiring the former to be at least as strong as the latter.
-            // So, for llvm 12, we upgrade the success ordering to a stronger
-            // one if necessary.
-            match (order, failure_order) {
-                (Relaxed, Acquire) => order = Acquire,
-                (Release, Acquire) => order = AcquireRelease,
-                (_, SequentiallyConsistent) => order = SequentiallyConsistent,
-                _ => {}
-            }
-        }
         unsafe {
             llvm::LLVMRustBuildAtomicCmpXchg(
                 self.llbuilder,
@@ -1444,51 +1429,37 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
         }
     }
 
-    fn fptoint_sat_broken_in_llvm(&self) -> bool {
-        match self.tcx.sess.target.arch.as_ref() {
-            // FIXME - https://bugs.llvm.org/show_bug.cgi?id=50083
-            "riscv64" => llvm_util::get_version() < (13, 0, 0),
-            _ => false,
-        }
-    }
-
     fn fptoint_sat(
         &mut self,
         signed: bool,
         val: &'ll Value,
         dest_ty: &'ll Type,
     ) -> Option<&'ll Value> {
-        if !self.fptoint_sat_broken_in_llvm() {
-            let src_ty = self.cx.val_ty(val);
-            let (float_ty, int_ty, vector_length) = if self.cx.type_kind(src_ty) == TypeKind::Vector
-            {
-                assert_eq!(self.cx.vector_length(src_ty), self.cx.vector_length(dest_ty));
-                (
-                    self.cx.element_type(src_ty),
-                    self.cx.element_type(dest_ty),
-                    Some(self.cx.vector_length(src_ty)),
-                )
-            } else {
-                (src_ty, dest_ty, None)
-            };
-            let float_width = self.cx.float_width(float_ty);
-            let int_width = self.cx.int_width(int_ty);
-
-            let instr = if signed { "fptosi" } else { "fptoui" };
-            let name = if let Some(vector_length) = vector_length {
-                format!(
-                    "llvm.{}.sat.v{}i{}.v{}f{}",
-                    instr, vector_length, int_width, vector_length, float_width
-                )
-            } else {
-                format!("llvm.{}.sat.i{}.f{}", instr, int_width, float_width)
-            };
-            let f =
-                self.declare_cfn(&name, llvm::UnnamedAddr::No, self.type_func(&[src_ty], dest_ty));
-            Some(self.call(self.type_func(&[src_ty], dest_ty), f, &[val], None))
+        let src_ty = self.cx.val_ty(val);
+        let (float_ty, int_ty, vector_length) = if self.cx.type_kind(src_ty) == TypeKind::Vector {
+            assert_eq!(self.cx.vector_length(src_ty), self.cx.vector_length(dest_ty));
+            (
+                self.cx.element_type(src_ty),
+                self.cx.element_type(dest_ty),
+                Some(self.cx.vector_length(src_ty)),
+            )
         } else {
-            None
-        }
+            (src_ty, dest_ty, None)
+        };
+        let float_width = self.cx.float_width(float_ty);
+        let int_width = self.cx.int_width(int_ty);
+
+        let instr = if signed { "fptosi" } else { "fptoui" };
+        let name = if let Some(vector_length) = vector_length {
+            format!(
+                "llvm.{}.sat.v{}i{}.v{}f{}",
+                instr, vector_length, int_width, vector_length, float_width
+            )
+        } else {
+            format!("llvm.{}.sat.i{}.f{}", instr, int_width, float_width)
+        };
+        let f = self.declare_cfn(&name, llvm::UnnamedAddr::No, self.type_func(&[src_ty], dest_ty));
+        Some(self.call(self.type_func(&[src_ty], dest_ty), f, &[val], None))
     }
 
     pub(crate) fn landing_pad(