From 3c2d43265c1691647a9e2adc57c7239a4366a624 Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Fri, 26 Aug 2022 10:37:51 +1000
Subject: [PATCH] Simplify arg capacity calculations.

Currently they try to be very precise. But they are wrong, i.e. they
don't match what's happening in the loop below. This code isn't hot
enough for it to matter that much.
---
 src/abi.rs | 22 +++-------------------
 1 file changed, 3 insertions(+), 19 deletions(-)

diff --git a/src/abi.rs b/src/abi.rs
index 7f313583c82..87b730d29cd 100644
--- a/src/abi.rs
+++ b/src/abi.rs
@@ -107,26 +107,10 @@ pub trait FnAbiGccExt<'gcc, 'tcx> {
 impl<'gcc, 'tcx> FnAbiGccExt<'gcc, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
     fn gcc_type(&self, cx: &CodegenCx<'gcc, 'tcx>) -> (Type<'gcc>, Vec<Type<'gcc>>, bool, FxHashSet<usize>) {
         let mut on_stack_param_indices = FxHashSet::default();
-        let args_capacity: usize = self.args.iter().map(|arg|
-            if arg.pad.is_some() {
-                1
-            }
-            else {
-                0
-            } +
-            if let PassMode::Pair(_, _) = arg.mode {
-                2
-            } else {
-                1
-            }
-        ).sum();
+
+        // This capacity calculation is approximate.
         let mut argument_tys = Vec::with_capacity(
-            if let PassMode::Indirect { .. } = self.ret.mode {
-                1
-            }
-            else {
-                0
-            } + args_capacity,
+            self.args.len() + if let PassMode::Indirect { .. } = self.ret.mode { 1 } else { 0 }
         );
 
         let return_ty =