215 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			215 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			LLVM
		
	
	
	
| ; RUN: llc -mtriple=armv4t-eabi %s -o -  | FileCheck %s --check-prefix=CHECK --check-prefix=V4T
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| ; RUN: llc -mtriple=armv6-eabi %s -o -   | FileCheck %s --check-prefix=CHECK --check-prefix=V6
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| ; RUN: llc -mtriple=armv6t2-eabi %s -o - | FileCheck %s --check-prefix=CHECK --check-prefix=V6T2
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| 
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| ; Check for several conditions that should result in USAT.
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| ; For example, the base test is equivalent to
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| ; x < 0 ? 0 : (x > k ? k : x) in C. All patterns that bound x
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| ; to the interval [0, k] where k + 1 is a power of 2 can be
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| ; transformed into USAT. At the end there are some tests
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| ; checking that conditionals are not transformed if they don't
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| ; match the right pattern.
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| 
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| ;
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| ; Base tests with different bit widths
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| ;
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| 
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| ; x < 0 ? 0 : (x > k ? k : x)
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| ; 32-bit base test
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| define i32 @unsigned_sat_base_32bit(i32 %x) #0 {
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| ; CHECK-LABEL: unsigned_sat_base_32bit:
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| ; V6: usat r0, #23, r0
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| ; V6T2: usat r0, #23, r0
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| ; V4T-NOT: usat
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| entry:
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|   %cmpLow = icmp slt i32 %x, 0
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|   %cmpUp = icmp sgt i32 %x, 8388607
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|   %saturateUp = select i1 %cmpUp, i32 8388607, i32 %x
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|   %saturateLow = select i1 %cmpLow, i32 0, i32 %saturateUp
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|   ret i32 %saturateLow
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| }
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| 
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| ; x < 0 ? 0 : (x > k ? k : x)
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| ; 16-bit base test
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| define i16 @unsigned_sat_base_16bit(i16 %x) #0 {
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| ; CHECK-LABEL: unsigned_sat_base_16bit:
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| ; V6: usat r0, #11, r0
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| ; V6T2: usat r0, #11, r0
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| ; V4T-NOT: usat
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| entry:
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|   %cmpLow = icmp slt i16 %x, 0
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|   %cmpUp = icmp sgt i16 %x, 2047
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|   %saturateUp = select i1 %cmpUp, i16 2047, i16 %x
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|   %saturateLow = select i1 %cmpLow, i16 0, i16 %saturateUp
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|   ret i16 %saturateLow
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| }
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| 
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| ; x < 0 ? 0 : (x > k ? k : x)
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| ; 8-bit base test
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| define i8 @unsigned_sat_base_8bit(i8 %x) #0 {
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| ; CHECK-LABEL: unsigned_sat_base_8bit:
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| ; V6: usat r0, #5, r0
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| ; V6T2: usat r0, #5, r0
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| ; V4T-NOT: usat
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| entry:
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|   %cmpLow = icmp slt i8 %x, 0
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|   %cmpUp = icmp sgt i8 %x, 31
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|   %saturateUp = select i1 %cmpUp, i8 31, i8 %x
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|   %saturateLow = select i1 %cmpLow, i8 0, i8 %saturateUp
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|   ret i8 %saturateLow
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| }
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| 
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| ;
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| ; Tests where the conditionals that check for upper and lower bounds,
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| ; or the < and > operators, are arranged in different ways. Only some
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| ; of the possible combinations that lead to USAT are tested.
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| ;
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| ; x < 0 ? 0 : (x < k ? x : k)
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| define i32 @unsigned_sat_lower_upper_1(i32 %x) #0 {
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| ; CHECK-LABEL: unsigned_sat_lower_upper_1:
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| ; V6: usat r0, #23, r0
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| ; V6T2: usat r0, #23, r0
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| ; V4T-NOT: usat
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| entry:
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|   %cmpLow = icmp slt i32 %x, 0
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|   %cmpUp = icmp slt i32 %x, 8388607
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|   %saturateUp = select i1 %cmpUp, i32 %x, i32 8388607
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|   %saturateLow = select i1 %cmpLow, i32 0, i32 %saturateUp
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|   ret i32 %saturateLow
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| }
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| 
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| ; x > 0 ? (x > k ? k : x) : 0
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| define i32 @unsigned_sat_lower_upper_2(i32 %x) #0 {
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| ; CHECK-LABEL: unsigned_sat_lower_upper_2:
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| ; V6: usat    r0, #23, r0
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| ; V6T2: usat    r0, #23, r0
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| ; V4T-NOT: usat
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| entry:
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|   %cmpLow = icmp sgt i32 %x, 0
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|   %cmpUp = icmp sgt i32 %x, 8388607
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|   %saturateUp = select i1 %cmpUp, i32 8388607, i32 %x
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|   %saturateLow = select i1 %cmpLow, i32 %saturateUp, i32 0
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|   ret i32 %saturateLow
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| }
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| 
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| ; x < k ? (x < 0 ? 0 : x) : k
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| define i32 @unsigned_sat_upper_lower_1(i32 %x) #0 {
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| ; CHECK-LABEL: unsigned_sat_upper_lower_1:
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| ; V6: usat    r0, #23, r0
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| ; V6T2: usat    r0, #23, r0
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| ; V4T-NOT: usat
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| entry:
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|   %cmpUp = icmp slt i32 %x, 8388607
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|   %cmpLow = icmp slt i32 %x, 0
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|   %saturateLow = select i1 %cmpLow, i32 0, i32 %x
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|   %saturateUp = select i1 %cmpUp, i32 %saturateLow, i32 8388607
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|   ret i32 %saturateUp
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| }
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| 
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| ; x > k ? k : (x < 0 ? 0 : x)
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| define i32 @unsigned_sat_upper_lower_2(i32 %x) #0 {
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| ; CHECK-LABEL: unsigned_sat_upper_lower_2:
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| ; V6: usat    r0, #23, r0
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| ; V6T2: usat    r0, #23, r0
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| ; V4T-NOT: usat
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| entry:
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|   %cmpUp = icmp sgt i32 %x, 8388607
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|   %cmpLow = icmp slt i32 %x, 0
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|   %saturateLow = select i1 %cmpLow, i32 0, i32 %x
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|   %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow
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|   ret i32 %saturateUp
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| }
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| 
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| ; k < x ? k : (x > 0 ? x : 0)
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| define i32 @unsigned_sat_upper_lower_3(i32 %x) #0 {
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| ; CHECK-LABEL: unsigned_sat_upper_lower_3:
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| ; V6: usat    r0, #23, r0
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| ; V6T2: usat    r0, #23, r0
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| ; V4T-NOT: usat
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| entry:
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|   %cmpUp = icmp slt i32 8388607, %x
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|   %cmpLow = icmp sgt i32 %x, 0
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|   %saturateLow = select i1 %cmpLow, i32 %x, i32 0
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|   %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow
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|   ret i32 %saturateUp
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| }
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| 
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| ;
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| ; The following tests check for patterns that should not transform
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| ; into USAT but are similar enough that could confuse the selector.
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| ;
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| ; x > k ? k : (x > 0 ? 0 : x)
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| ; First condition upper-saturates, second doesn't lower-saturate.
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| define i32 @no_unsigned_sat_missing_lower(i32 %x) #0 {
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| ; CHECK-LABEL: no_unsigned_sat_missing_lower
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| ; CHECK-NOT: usat
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| entry:
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|   %cmpUp = icmp sgt i32 %x, 8388607
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|   %cmpLow = icmp sgt i32 %x, 0
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|   %saturateLow = select i1 %cmpLow, i32 0, i32 %x
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|   %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow
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|   ret i32 %saturateUp
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| }
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| 
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| ; x < k ? k : (x < 0 ? 0 : x)
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| ; Second condition lower-saturates, first doesn't upper-saturate.
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| define i32 @no_unsigned_sat_missing_upper(i32 %x) #0 {
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| ; CHECK-LABEL: no_unsigned_sat_missing_upper:
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| ; CHECK-NOT: usat
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| entry:
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|   %cmpUp = icmp slt i32 %x, 8388607
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|   %cmpLow = icmp slt i32 %x, 0
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|   %saturateLow = select i1 %cmpLow, i32 0, i32 %x
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|   %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow
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|   ret i32 %saturateUp
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| }
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| 
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| ; Lower constant is different in the select and in the compare
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| define i32 @no_unsigned_sat_incorrect_constant(i32 %x) #0 {
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| ; CHECK-LABEL: no_unsigned_sat_incorrect_constant:
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| ; CHECK-NOT: usat
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| entry:
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|   %cmpUp = icmp sgt i32 %x, 8388607
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|   %cmpLow = icmp slt i32 %x, 0
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|   %saturateLow = select i1 %cmpLow, i32 -1, i32 %x
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|   %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow
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|   ret i32 %saturateUp
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| }
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| 
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| ; The interval is not [0, k]
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| define i32 @no_unsigned_sat_incorrect_interval(i32 %x) #0 {
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| ; CHECK-LABEL: no_unsigned_sat_incorrect_interval:
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| ; CHECK-NOT: usat
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| entry:
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|   %cmpUp = icmp sgt i32 %x, 8388607
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|   %cmpLow = icmp slt i32 %x, -4
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|   %saturateLow = select i1 %cmpLow, i32 -4, i32 %x
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|   %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow
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|   ret i32 %saturateUp
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| }
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| 
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| ; The returned value (y) is not the same as the tested value (x).
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| define i32 @no_unsigned_sat_incorrect_return(i32 %x, i32 %y) #0 {
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| ; CHECK-LABEL: no_unsigned_sat_incorrect_return:
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| ; CHECK-NOT: usat
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| entry:
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|   %cmpUp = icmp sgt i32 %x, 8388607
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|   %cmpLow = icmp slt i32 %x, 0
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|   %saturateLow = select i1 %cmpLow, i32 0, i32 %y
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|   %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow
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|   ret i32 %saturateUp
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| }
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| 
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| ; One of the values in a compare (y) is not the same as the rest
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| ; of the compare and select values (x).
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| define i32 @no_unsigned_sat_incorrect_compare(i32 %x, i32 %y) #0 {
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| ; CHECK-LABEL: no_unsigned_sat_incorrect_compare:
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| ; CHECK-NOT: usat
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| entry:
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|   %cmpUp = icmp sgt i32 %x, 8388607
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|   %cmpLow = icmp slt i32 %y, 0
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|   %saturateLow = select i1 %cmpLow, i32 0, i32 %x
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|   %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow
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|   ret i32 %saturateUp
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| }
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