Hi hackers,
I find there are some unnecessary load/store instructions being
emitted by the JIT compiler.
E.g.,
```
v_boolnull = l_load(b, TypeStorageBool, v_resnullp, "");
v_boolvalue = l_load(b, TypeSizeT, v_resvaluep, "");
/* set resnull to boolnull */
LLVMBuildStore(b, v_boolnull, v_resnullp);
/* set revalue to boolvalue */
LLVMBuildStore(b, v_boolvalue, v_resvaluep);
```
v_boolnull is loaded from v_resnullp and stored to v_resnullp immediately.
v_boolvalue is loaded from v_resvaluep and stored to v_resvaluep immediately.
The attached patch is trying to fix them.
Best Regards,
Xing
From 6c7503b9e92c10b3dd9e6d33391273b854d53437 Mon Sep 17 00:00:00 2001
From: Xing Guo <higuox...@gmail.com>
Date: Fri, 30 Aug 2024 11:43:45 +0800
Subject: [PATCH] JIT: Remove some unnecessary instructions.
There're some unnecessary instructions being emitted by the JIT
compiler. This patch removes them.
---
src/backend/jit/llvm/llvmjit_expr.c | 15 +--------------
1 file changed, 1 insertion(+), 14 deletions(-)
diff --git a/src/backend/jit/llvm/llvmjit_expr.c b/src/backend/jit/llvm/llvmjit_expr.c
index 48ccdb942a..1edc476c59 100644
--- a/src/backend/jit/llvm/llvmjit_expr.c
+++ b/src/backend/jit/llvm/llvmjit_expr.c
@@ -720,11 +720,6 @@ llvm_compile_expr(ExprState *state)
v_boolnull = l_load(b, TypeStorageBool, v_resnullp, "");
v_boolvalue = l_load(b, TypeSizeT, v_resvaluep, "");
- /* set resnull to boolnull */
- LLVMBuildStore(b, v_boolnull, v_resnullp);
- /* set revalue to boolvalue */
- LLVMBuildStore(b, v_boolvalue, v_resvaluep);
-
/* check if current input is NULL */
LLVMBuildCondBr(b,
LLVMBuildICmp(b, LLVMIntEQ, v_boolnull,
@@ -816,11 +811,6 @@ llvm_compile_expr(ExprState *state)
v_boolnull = l_load(b, TypeStorageBool, v_resnullp, "");
v_boolvalue = l_load(b, TypeSizeT, v_resvaluep, "");
- /* set resnull to boolnull */
- LLVMBuildStore(b, v_boolnull, v_resnullp);
- /* set revalue to boolvalue */
- LLVMBuildStore(b, v_boolvalue, v_resvaluep);
-
LLVMBuildCondBr(b,
LLVMBuildICmp(b, LLVMIntEQ, v_boolnull,
l_sbool_const(1), ""),
@@ -875,10 +865,8 @@ llvm_compile_expr(ExprState *state)
case EEOP_BOOL_NOT_STEP:
{
LLVMValueRef v_boolvalue;
- LLVMValueRef v_boolnull;
LLVMValueRef v_negbool;
- v_boolnull = l_load(b, TypeStorageBool, v_resnullp, "");
v_boolvalue = l_load(b, TypeSizeT, v_resvaluep, "");
v_negbool = LLVMBuildZExt(b,
@@ -887,8 +875,7 @@ llvm_compile_expr(ExprState *state)
l_sizet_const(0),
""),
TypeSizeT, "");
- /* set resnull to boolnull */
- LLVMBuildStore(b, v_boolnull, v_resnullp);
+
/* set revalue to !boolvalue */
LLVMBuildStore(b, v_negbool, v_resvaluep);
--
2.46.0
