Auto merge of #126991 - cjgillot:gvn-prof, r=oli-obk

Accelerate GVN a little

This PR addresses a few inefficiencies I've seen in callgrind profiles.

Commits are independent.

Only the first commit introduces a change in behaviour: we stop substituting some constant pointers. But we keep propagating their contents that have no provenance, so we don't lose much.

r? `@saethlin`

10 files changed, 31 insertions, 55 deletions

diff --git a/tests/incremental/hashes/for_loops.rs b/tests/incremental/hashes/for_loops.rs
index 9cd99bf76b7..b827ad9cc6f 100644
--- a/tests/incremental/hashes/for_loops.rs
+++ b/tests/incremental/hashes/for_loops.rs
@@ -103,9 +103,9 @@ pub fn change_iterable() {
 }
 
 #[cfg(not(any(cfail1,cfail4)))]
-#[rustc_clean(cfg="cfail2", except="opt_hir_owner_nodes, promoted_mir, optimized_mir")]
+#[rustc_clean(cfg="cfail2", except="opt_hir_owner_nodes, promoted_mir")]
 #[rustc_clean(cfg="cfail3")]
-#[rustc_clean(cfg="cfail5", except="opt_hir_owner_nodes, promoted_mir, optimized_mir")]
+#[rustc_clean(cfg="cfail5", except="opt_hir_owner_nodes, promoted_mir")]
 #[rustc_clean(cfg="cfail6")]
 pub fn change_iterable() {
     let mut _x = 0;
diff --git a/tests/mir-opt/const_prop/slice_len.main.GVN.32bit.panic-abort.diff b/tests/mir-opt/const_prop/slice_len.main.GVN.32bit.panic-abort.diff
index 8415789de6e..21d91d0320a 100644
--- a/tests/mir-opt/const_prop/slice_len.main.GVN.32bit.panic-abort.diff
+++ b/tests/mir-opt/const_prop/slice_len.main.GVN.32bit.panic-abort.diff
@@ -22,12 +22,11 @@
           StorageLive(_3);
           StorageLive(_4);
           _9 = const main::promoted[0];
--         _4 = _9;
+          _4 = _9;
 -         _3 = _4;
 -         _2 = move _3 as &[u32] (PointerCoercion(Unsize));
-+         _4 = const {ALLOC0<imm>: &[u32; 3]};
-+         _3 = const {ALLOC0<imm>: &[u32; 3]};
-+         _2 = const {ALLOC0<imm>: &[u32; 3]} as &[u32] (PointerCoercion(Unsize));
++         _3 = _9;
++         _2 = _9 as &[u32] (PointerCoercion(Unsize));
           StorageDead(_3);
           StorageLive(_6);
           _6 = const 1_usize;
@@ -50,6 +49,4 @@
           return;
       }
   }
-+ 
-+ ALLOC0 (size: 12, align: 4) { .. }
   
diff --git a/tests/mir-opt/const_prop/slice_len.main.GVN.32bit.panic-unwind.diff b/tests/mir-opt/const_prop/slice_len.main.GVN.32bit.panic-unwind.diff
index fea7caac3cd..889114c9862 100644
--- a/tests/mir-opt/const_prop/slice_len.main.GVN.32bit.panic-unwind.diff
+++ b/tests/mir-opt/const_prop/slice_len.main.GVN.32bit.panic-unwind.diff
@@ -22,12 +22,11 @@
           StorageLive(_3);
           StorageLive(_4);
           _9 = const main::promoted[0];
--         _4 = _9;
+          _4 = _9;
 -         _3 = _4;
 -         _2 = move _3 as &[u32] (PointerCoercion(Unsize));
-+         _4 = const {ALLOC0<imm>: &[u32; 3]};
-+         _3 = const {ALLOC0<imm>: &[u32; 3]};
-+         _2 = const {ALLOC0<imm>: &[u32; 3]} as &[u32] (PointerCoercion(Unsize));
++         _3 = _9;
++         _2 = _9 as &[u32] (PointerCoercion(Unsize));
           StorageDead(_3);
           StorageLive(_6);
           _6 = const 1_usize;
@@ -50,6 +49,4 @@
           return;
       }
   }
-+ 
-+ ALLOC0 (size: 12, align: 4) { .. }
   
diff --git a/tests/mir-opt/const_prop/slice_len.main.GVN.64bit.panic-abort.diff b/tests/mir-opt/const_prop/slice_len.main.GVN.64bit.panic-abort.diff
index 8415789de6e..21d91d0320a 100644
--- a/tests/mir-opt/const_prop/slice_len.main.GVN.64bit.panic-abort.diff
+++ b/tests/mir-opt/const_prop/slice_len.main.GVN.64bit.panic-abort.diff
@@ -22,12 +22,11 @@
           StorageLive(_3);
           StorageLive(_4);
           _9 = const main::promoted[0];
--         _4 = _9;
+          _4 = _9;
 -         _3 = _4;
 -         _2 = move _3 as &[u32] (PointerCoercion(Unsize));
-+         _4 = const {ALLOC0<imm>: &[u32; 3]};
-+         _3 = const {ALLOC0<imm>: &[u32; 3]};
-+         _2 = const {ALLOC0<imm>: &[u32; 3]} as &[u32] (PointerCoercion(Unsize));
++         _3 = _9;
++         _2 = _9 as &[u32] (PointerCoercion(Unsize));
           StorageDead(_3);
           StorageLive(_6);
           _6 = const 1_usize;
@@ -50,6 +49,4 @@
           return;
       }
   }
-+ 
-+ ALLOC0 (size: 12, align: 4) { .. }
   
diff --git a/tests/mir-opt/const_prop/slice_len.main.GVN.64bit.panic-unwind.diff b/tests/mir-opt/const_prop/slice_len.main.GVN.64bit.panic-unwind.diff
index fea7caac3cd..889114c9862 100644
--- a/tests/mir-opt/const_prop/slice_len.main.GVN.64bit.panic-unwind.diff
+++ b/tests/mir-opt/const_prop/slice_len.main.GVN.64bit.panic-unwind.diff
@@ -22,12 +22,11 @@
           StorageLive(_3);
           StorageLive(_4);
           _9 = const main::promoted[0];
--         _4 = _9;
+          _4 = _9;
 -         _3 = _4;
 -         _2 = move _3 as &[u32] (PointerCoercion(Unsize));
-+         _4 = const {ALLOC0<imm>: &[u32; 3]};
-+         _3 = const {ALLOC0<imm>: &[u32; 3]};
-+         _2 = const {ALLOC0<imm>: &[u32; 3]} as &[u32] (PointerCoercion(Unsize));
++         _3 = _9;
++         _2 = _9 as &[u32] (PointerCoercion(Unsize));
           StorageDead(_3);
           StorageLive(_6);
           _6 = const 1_usize;
@@ -50,6 +49,4 @@
           return;
       }
   }
-+ 
-+ ALLOC0 (size: 12, align: 4) { .. }
   
diff --git a/tests/mir-opt/const_prop/slice_len.rs b/tests/mir-opt/const_prop/slice_len.rs
index 221fb18f92c..3d1b58965ac 100644
--- a/tests/mir-opt/const_prop/slice_len.rs
+++ b/tests/mir-opt/const_prop/slice_len.rs
@@ -7,7 +7,7 @@
 fn main() {
     // CHECK-LABEL: fn main(
     // CHECK: debug a => [[a:_.*]];
-    // CHECK: [[slice:_.*]] = const {{.*}} as &[u32] (PointerCoercion(Unsize));
+    // CHECK: [[slice:_.*]] = {{.*}} as &[u32] (PointerCoercion(Unsize));
     // CHECK: assert(const true,
     // CHECK: [[a]] = const 2_u32;
     let a = (&[1u32, 2, 3] as &[u32])[1];
diff --git a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-abort.diff b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-abort.diff
index 959efa2a548..30c122ddea0 100644
--- a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-abort.diff
+++ b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-abort.diff
@@ -73,13 +73,12 @@
           StorageLive(_6);
           StorageLive(_7);
           _9 = const main::promoted[0];
--         _7 = _9;
-+         _7 = const {ALLOC1<imm>: &std::alloc::Global};
+          _7 = _9;
           StorageLive(_8);
 -         _8 = _1;
 -         _6 = std::alloc::Global::alloc_impl(move _7, move _8, const false) -> [return: bb4, unwind unreachable];
 +         _8 = const Layout {{ size: Indirect { alloc_id: ALLOC0, offset: Size(4 bytes) }: usize, align: std::ptr::Alignment(Scalar(0x00000000): std::ptr::alignment::AlignmentEnum) }};
-+         _6 = std::alloc::Global::alloc_impl(const {ALLOC1<imm>: &std::alloc::Global}, const Layout {{ size: Indirect { alloc_id: ALLOC0, offset: Size(4 bytes) }: usize, align: std::ptr::Alignment(Scalar(0x00000000): std::ptr::alignment::AlignmentEnum) }}, const false) -> [return: bb4, unwind unreachable];
++         _6 = std::alloc::Global::alloc_impl(_9, const Layout {{ size: Indirect { alloc_id: ALLOC0, offset: Size(4 bytes) }: usize, align: std::ptr::Alignment(Scalar(0x00000000): std::ptr::alignment::AlignmentEnum) }}, const false) -> [return: bb4, unwind unreachable];
       }
   
       bb4: {
@@ -119,11 +118,9 @@
 +         nop;
           return;
       }
-  }
++ }
 + 
 + ALLOC0 (size: 8, align: 4) {
 +     00 00 00 00 __ __ __ __                         │ ....░░░░
-+ }
-+ 
-+ ALLOC1 (size: 0, align: 1) {}
+  }
   
diff --git a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-unwind.diff b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-unwind.diff
index 4a37c860320..93449462c3d 100644
--- a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-unwind.diff
+++ b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.32bit.panic-unwind.diff
@@ -81,13 +81,12 @@
           StorageLive(_6);
           StorageLive(_7);
           _9 = const main::promoted[0];
--         _7 = _9;
-+         _7 = const {ALLOC1<imm>: &std::alloc::Global};
+          _7 = _9;
           StorageLive(_8);
 -         _8 = _1;
 -         _6 = std::alloc::Global::alloc_impl(move _7, move _8, const false) -> [return: bb5, unwind continue];
 +         _8 = const Layout {{ size: Indirect { alloc_id: ALLOC0, offset: Size(4 bytes) }: usize, align: std::ptr::Alignment(Scalar(0x00000000): std::ptr::alignment::AlignmentEnum) }};
-+         _6 = std::alloc::Global::alloc_impl(const {ALLOC1<imm>: &std::alloc::Global}, const Layout {{ size: Indirect { alloc_id: ALLOC0, offset: Size(4 bytes) }: usize, align: std::ptr::Alignment(Scalar(0x00000000): std::ptr::alignment::AlignmentEnum) }}, const false) -> [return: bb5, unwind continue];
++         _6 = std::alloc::Global::alloc_impl(_9, const Layout {{ size: Indirect { alloc_id: ALLOC0, offset: Size(4 bytes) }: usize, align: std::ptr::Alignment(Scalar(0x00000000): std::ptr::alignment::AlignmentEnum) }}, const false) -> [return: bb5, unwind continue];
       }
   
       bb5: {
@@ -95,11 +94,9 @@
           StorageDead(_7);
           _5 = Result::<NonNull<[u8]>, std::alloc::AllocError>::unwrap(move _6) -> [return: bb1, unwind continue];
       }
-  }
++ }
 + 
 + ALLOC0 (size: 8, align: 4) {
 +     00 00 00 00 __ __ __ __                         │ ....░░░░
-+ }
-+ 
-+ ALLOC1 (size: 0, align: 1) {}
+  }
   
diff --git a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-abort.diff b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-abort.diff
index 97f5245a8c9..44435956ec4 100644
--- a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-abort.diff
+++ b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-abort.diff
@@ -73,13 +73,12 @@
           StorageLive(_6);
           StorageLive(_7);
           _9 = const main::promoted[0];
--         _7 = _9;
-+         _7 = const {ALLOC1<imm>: &std::alloc::Global};
+          _7 = _9;
           StorageLive(_8);
 -         _8 = _1;
 -         _6 = std::alloc::Global::alloc_impl(move _7, move _8, const false) -> [return: bb4, unwind unreachable];
 +         _8 = const Layout {{ size: Indirect { alloc_id: ALLOC0, offset: Size(8 bytes) }: usize, align: std::ptr::Alignment(Scalar(0x0000000000000000): std::ptr::alignment::AlignmentEnum) }};
-+         _6 = std::alloc::Global::alloc_impl(const {ALLOC1<imm>: &std::alloc::Global}, const Layout {{ size: Indirect { alloc_id: ALLOC0, offset: Size(8 bytes) }: usize, align: std::ptr::Alignment(Scalar(0x0000000000000000): std::ptr::alignment::AlignmentEnum) }}, const false) -> [return: bb4, unwind unreachable];
++         _6 = std::alloc::Global::alloc_impl(_9, const Layout {{ size: Indirect { alloc_id: ALLOC0, offset: Size(8 bytes) }: usize, align: std::ptr::Alignment(Scalar(0x0000000000000000): std::ptr::alignment::AlignmentEnum) }}, const false) -> [return: bb4, unwind unreachable];
       }
   
       bb4: {
@@ -119,11 +118,9 @@
 +         nop;
           return;
       }
-  }
++ }
 + 
 + ALLOC0 (size: 16, align: 8) {
 +     00 00 00 00 00 00 00 00 __ __ __ __ __ __ __ __ │ ........░░░░░░░░
-+ }
-+ 
-+ ALLOC1 (size: 0, align: 1) {}
+  }
   
diff --git a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-unwind.diff b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-unwind.diff
index ec2e95fecb6..c958480a9c7 100644
--- a/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-unwind.diff
+++ b/tests/mir-opt/pre-codegen/issue_117368_print_invalid_constant.main.GVN.64bit.panic-unwind.diff
@@ -81,13 +81,12 @@
           StorageLive(_6);
           StorageLive(_7);
           _9 = const main::promoted[0];
--         _7 = _9;
-+         _7 = const {ALLOC1<imm>: &std::alloc::Global};
+          _7 = _9;
           StorageLive(_8);
 -         _8 = _1;
 -         _6 = std::alloc::Global::alloc_impl(move _7, move _8, const false) -> [return: bb5, unwind continue];
 +         _8 = const Layout {{ size: Indirect { alloc_id: ALLOC0, offset: Size(8 bytes) }: usize, align: std::ptr::Alignment(Scalar(0x0000000000000000): std::ptr::alignment::AlignmentEnum) }};
-+         _6 = std::alloc::Global::alloc_impl(const {ALLOC1<imm>: &std::alloc::Global}, const Layout {{ size: Indirect { alloc_id: ALLOC0, offset: Size(8 bytes) }: usize, align: std::ptr::Alignment(Scalar(0x0000000000000000): std::ptr::alignment::AlignmentEnum) }}, const false) -> [return: bb5, unwind continue];
++         _6 = std::alloc::Global::alloc_impl(_9, const Layout {{ size: Indirect { alloc_id: ALLOC0, offset: Size(8 bytes) }: usize, align: std::ptr::Alignment(Scalar(0x0000000000000000): std::ptr::alignment::AlignmentEnum) }}, const false) -> [return: bb5, unwind continue];
       }
   
       bb5: {
@@ -95,11 +94,9 @@
           StorageDead(_7);
           _5 = Result::<NonNull<[u8]>, std::alloc::AllocError>::unwrap(move _6) -> [return: bb1, unwind continue];
       }
-  }
++ }
 + 
 + ALLOC0 (size: 16, align: 8) {
 +     00 00 00 00 00 00 00 00 __ __ __ __ __ __ __ __ │ ........░░░░░░░░
-+ }
-+ 
-+ ALLOC1 (size: 0, align: 1) {}
+  }