jit: Correct parameter type for generated expression evaluation functions.

clang only uses the 'i1' type for scalar booleans, not for pointers to
booleans (as the pointer might be pointing into a larger memory
allocation). Therefore a pointer-to-bool needs to the "storage" boolean.

There's no known case of wrong code generation due to this, but it seems quite
possible that it could cause problems (see e.g. 72559438f92).

Author: Andres Freund
Discussion: https://postgr.es/m/20201207212142.wz5tnbk2jsaqzogb@alap3.anarazel.de
Backpatch: 11-, where jit support was added

diff --git a/src/backend/jit/llvm/llvmjit_expr.c b/src/backend/jit/llvm/llvmjit_expr.c
index cca5c117a0eeffe676fede4daafc28f9ca81c83e..b5e6b6515c503fbcfb84430e062d42a62ae2895d 100644 (file)
--- a/src/backend/jit/llvm/llvmjit_expr.c
+++ b/src/backend/jit/llvm/llvmjit_expr.c
@@ -155,7 +155,7 @@ llvm_compile_expr(ExprState *state)
 
        param_types[0] = l_ptr(StructExprState);    /* state */
        param_types[1] = l_ptr(StructExprContext);  /* econtext */
-       param_types[2] = l_ptr(TypeParamBool);  /* isnull */
+       param_types[2] = l_ptr(TypeStorageBool);    /* isnull */
 
        eval_sig = LLVMFunctionType(TypeSizeT,
                                    param_types, lengthof(param_types),
@@ -265,8 +265,6 @@ llvm_compile_expr(ExprState *state)
 
                    v_tmpvalue = LLVMBuildLoad(b, v_tmpvaluep, "");
                    v_tmpisnull = LLVMBuildLoad(b, v_tmpisnullp, "");
-                   v_tmpisnull =
-                       LLVMBuildTrunc(b, v_tmpisnull, TypeParamBool, "");
 
                    LLVMBuildStore(b, v_tmpisnull, v_isnullp);