[Qemu-devel] [PATCH v2 2/2] hw/openrisc: avoid undefined shift in openrisc_pic_cpu_handler()

[Xi Wang]

In C99 signed shift (1 << 31) is undefined behavior, since the result
exceeds INT_MAX.  Use 1U instead and move the shift after the check.

Cc: Jia Liu <address@hidden>
Cc: Paolo Bonzini <address@hidden>
Signed-off-by: Xi Wang <address@hidden>
---
 hw/openrisc/pic_cpu.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/hw/openrisc/pic_cpu.c b/hw/openrisc/pic_cpu.c
index 3fcee02..2af1d60 100644
--- a/hw/openrisc/pic_cpu.c
+++ b/hw/openrisc/pic_cpu.c
@@ -26,12 +26,14 @@ static void openrisc_pic_cpu_handler(void *opaque, int irq, 
int level)
 {
     OpenRISCCPU *cpu = (OpenRISCCPU *)opaque;
     CPUState *cs = CPU(cpu);
-    uint32_t irq_bit = 1 << irq;
+    uint32_t irq_bit;
 
     if (irq > 31 || irq < 0) {
         return;
     }
 
+    irq_bit = 1U << irq;
+
     if (level) {
         cpu->env.picsr |= irq_bit;
     } else {
-- 
1.8.1.2