From 7710c76d56d0614ae7d029ac19be9a2cef0c76d6 Mon Sep 17 00:00:00 2001 From: David Given Date: Sat, 7 Jan 2017 13:17:39 +0100 Subject: [PATCH] Introduce sequence points before store instructions to prevent loads from the same address being delayed until after the store (at which point they'll return the wrong value). --- mach/proto/mcg/treebuilder.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/mach/proto/mcg/treebuilder.c b/mach/proto/mcg/treebuilder.c index 2ead527fc..5b2a1b93d 100644 --- a/mach/proto/mcg/treebuilder.c +++ b/mach/proto/mcg/treebuilder.c @@ -119,6 +119,25 @@ static struct ir* appendir(struct ir* ir) return ir; } +static void sequence_point(void) +{ + int i; + + /* Ensures that any partially-evaluated expressions on the stack are executed right + * now. This typically needs to happen before store operations, to prevents loads of + * the same address being delayed until after the store (at which point they'll + * return incorrect values). + */ + + assert(current_bb != NULL); + + for (i=0; iirs, ir); + } +} + static void materialise_stack(void) { int i; @@ -229,6 +248,8 @@ static struct ir* store(int size, struct ir* address, int offset, struct ir* val { int opcode; + sequence_point(); + if (size == 1) { opcode = IR_STOREB; @@ -475,6 +496,7 @@ static void insn_simple(int opcode) case op_sim: { + sequence_point(); appendir( new_ir2( (EM_wordsize == 2) ? IR_STORE : IR_STOREH, EM_wordsize, @@ -1497,6 +1519,7 @@ static void insn_lvalue(int opcode, const char* label, arith offset) break; case op_ste: + sequence_point(); appendir( new_ir2( IR_STORE, EM_wordsize, @@ -1507,6 +1530,7 @@ static void insn_lvalue(int opcode, const char* label, arith offset) break; case op_sde: + sequence_point(); appendir( new_ir2( IR_STORE, EM_wordsize*2, @@ -1517,6 +1541,7 @@ static void insn_lvalue(int opcode, const char* label, arith offset) break; case op_zre: + sequence_point(); appendir( new_ir2( IR_STORE, EM_wordsize, @@ -1527,6 +1552,7 @@ static void insn_lvalue(int opcode, const char* label, arith offset) break; case op_ine: + sequence_point(); appendir( new_ir2( IR_STORE, EM_wordsize, @@ -1544,6 +1570,7 @@ static void insn_lvalue(int opcode, const char* label, arith offset) break; case op_dee: + sequence_point(); appendir( new_ir2( IR_STORE, EM_wordsize, -- 2.34.1