[PATCH 1/3] libsframe: simplify SFrame FRE range check

[Jens Remus <jremus@linux.ibm.com>]

For regular SFrame FDEs the PC offset from function start address must
be within a SFrame FRE's start IP offset and end IP offset.  For type
PC mask FDEs the masked PC offset must be within that range.

libsframe/
	* sframe.c (sframe_fre_check_range_p): Simplify.

Signed-off-by: Jens Remus <jremus@linux.ibm.com>
---

Notes (jremus):
    @Indu: This could be squashed into your "libsframe: fix issue in
    finding FRE in SFRAME_FDE_TYPE_PCMASK type SFrame FDEs" or kept
    separately.

 libsframe/sframe.c | 32 ++++++++------------------------
 1 file changed, 8 insertions(+), 24 deletions(-)

diff --git a/libsframe/sframe.c b/libsframe/sframe.c
index 85457e4d6602..c1bc692829a9 100644
--- a/libsframe/sframe.c
+++ b/libsframe/sframe.c
@@ -372,43 +372,27 @@ sframe_fre_check_range_p (sframe_func_desc_entry *fdep,
 			  int32_t start_ip_offset, int32_t end_ip_offset,
 			  int32_t pc)
 {
-  int32_t start_ip, end_ip;
   int32_t func_start_addr;
   uint8_t rep_block_size;
   uint32_t fde_type;
-  int32_t masked_pc;
+  int32_t pc_offset;
   bool mask_p;
-  bool ret;
-
-  ret = false;
 
   if (!fdep)
-    return ret;
+    return false;
 
   func_start_addr = fdep->sfde_func_start_address;
   fde_type = sframe_get_fde_type (fdep);
   mask_p = (fde_type == SFRAME_FDE_TYPE_PCMASK);
   rep_block_size = fdep->sfde_func_rep_size;
 
-  if (!mask_p)
-    {
-      start_ip = start_ip_offset + func_start_addr;
-      end_ip = end_ip_offset + func_start_addr;
-      ret = ((start_ip <= pc) && (end_ip >= pc));
-    }
-  else
-    {
-      /* For SFrame FDEs encoding information for repetitive pattern of insns,
-	 masking with the rep_block_size is necessary to find the matching FRE.
-	 start_ip_offset and end_ip_offset are _unsigned_values_ identifying
-	 the SFrame FRE.  So, perform a calculation to first get the distance
-	 between the pc and func_start_addr, followed by modulo to find the
-	 fitting range.  */
-      masked_pc = (pc - func_start_addr) % rep_block_size;
-      ret = ((start_ip_offset <= masked_pc) && (end_ip_offset >= masked_pc));
-    }
+  pc_offset = pc - func_start_addr;
+  /* For SFrame FDEs encoding information for repetitive pattern of insns,
+     masking with the rep_block_size is necessary to find the matching FRE.  */
+  if (mask_p)
+    pc_offset = pc_offset % rep_block_size;
 
-  return ret;
+  return (start_ip_offset <= pc_offset) && (end_ip_offset >= pc_offset);
 }
 
 static int
-- 
2.45.2