[WebAssembly] Fix immediate of rethrow when throwing to caller

Summary:
Currently when assigning depths 'rethrow' does not take the whole
control flow stack into accounts but only considers EH pad stacks. When
assigning depth immmediates to rethrows, in normal cases it is done
correctly but when a rethrow instruction throws up to a caller, i.e., we
convert a pseudo RETHROW_TO_CALLER instruction to a rethrow, it
mistakenly compute the whole stack depth.

Reviewers: dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D53619

llvm-svn: 345223

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
index 93ca670..a3b3901 100644 (file)
--- a/llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
@@ -767,7 +767,7 @@ void WebAssemblyCFGStackify::rewriteDepthImmediates(MachineFunction &MF) {
       case WebAssembly::RETHROW_TO_CALLER: {
         MachineInstr *Rethrow =
             BuildMI(MBB, MI, MI.getDebugLoc(), TII.get(WebAssembly::RETHROW))
-                .addImm(Stack.size());
+                .addImm(EHPadStack.size());
         MI.eraseFromParent();
         I = MachineBasicBlock::reverse_iterator(Rethrow);
         break;

diff --git a/llvm/test/CodeGen/WebAssembly/cfg-stackify-eh.mir b/llvm/test/CodeGen/WebAssembly/cfg-stackify-eh.mir
index 9038f68..b675790 100644 (file)
--- a/llvm/test/CodeGen/WebAssembly/cfg-stackify-eh.mir
+++ b/llvm/test/CodeGen/WebAssembly/cfg-stackify-eh.mir
@@ -180,7 +180,7 @@ body: |
     RETHROW_TO_CALLER implicit-def $arguments
   ; CHECK-LABEL: bb.7:
     ; CHECK-NEXT: END_TRY
-    ; CHECK: RETHROW 3
+    ; CHECK: RETHROW 0
 
   bb.8:
   ; predecessors: %bb.2, %bb.4