Make pointer max constant not overflow

CAD97 · CAD97 · commit ed3502f7831f · 2022-04-24T18:38:26.000-05:00
diff --git a/compiler/rustc_codegen_ssa/src/glue.rs b/compiler/rustc_codegen_ssa/src/glue.rs
@@ -44,8 +44,9 @@ pub fn size_and_align_of_dst<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
                 bx.const_usize(unit.size.bytes()),
                 info.unwrap(),
             );
+            let ptr_max = bx.data_layout().pointer_size.truncate(u128::MAX) as u64;
             (
-                bx.select(overflow, bx.const_usize(u64::MAX), size),
+                bx.select(overflow, bx.const_usize(ptr_max), size),
                 bx.const_usize(unit.align.abi.bytes()),
             )
         }

Original file line number	Diff line number	Diff line change
`@@ -44,8 +44,9 @@ pub fn size_and_align_of_dst<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(`
`44`	`44`	`bx.const_usize(unit.size.bytes()),`
`45`	`45`	`info.unwrap(),`
`46`	`46`	`);`
	`47`	`+ let ptr_max = bx.data_layout().pointer_size.truncate(u128::MAX) as u64;`
`47`	`48`	`(`
`48`		`- bx.select(overflow, bx.const_usize(u64::MAX), size),`
	`49`	`+ bx.select(overflow, bx.const_usize(ptr_max), size),`
`49`	`50`	`bx.const_usize(unit.align.abi.bytes()),`
`50`	`51`	`)`
`51`	`52`	`}`