| ; RUN: llc -mtriple=armv4t-eabi %s -o - | FileCheck %s --check-prefix=CHECK --check-prefix=V4T |
| ; RUN: llc -mtriple=armv6t2-eabi %s -o - | FileCheck %s --check-prefix=CHECK --check-prefix=V6T2 |
| |
| ; Check for several conditions that should result in SSAT. |
| ; For example, the base test is equivalent to |
| ; x < -k ? -k : (x > k ? k : x) in C. All patterns that bound x |
| ; to the interval [-k, k] where k is a power of 2 can be |
| ; transformed into SSAT. At the end there are some tests |
| ; checking that conditionals are not transformed if they don't |
| ; match the right pattern. |
| |
| ; |
| ; Base tests with different bit widths |
| ; |
| |
| ; x < -k ? -k : (x > k ? k : x) |
| ; 32-bit base test |
| define i32 @sat_base_32bit(i32 %x) #0 { |
| ; CHECK-LABEL: sat_base_32bit: |
| ; V6T2: ssat r0, #24, r0 |
| ; V4T-NOT: ssat |
| entry: |
| %cmpLow = icmp slt i32 %x, -8388608 |
| %cmpUp = icmp sgt i32 %x, 8388607 |
| %saturateUp = select i1 %cmpUp, i32 8388607, i32 %x |
| %saturateLow = select i1 %cmpLow, i32 -8388608, i32 %saturateUp |
| ret i32 %saturateLow |
| } |
| |
| ; x < -k ? -k : (x > k ? k : x) |
| ; 16-bit base test |
| define i16 @sat_base_16bit(i16 %x) #0 { |
| ; CHECK-LABEL: sat_base_16bit: |
| ; V6T2: ssat r0, #12, r0 |
| ; V4T-NOT: ssat |
| entry: |
| %cmpLow = icmp slt i16 %x, -2048 |
| %cmpUp = icmp sgt i16 %x, 2047 |
| %saturateUp = select i1 %cmpUp, i16 2047, i16 %x |
| %saturateLow = select i1 %cmpLow, i16 -2048, i16 %saturateUp |
| ret i16 %saturateLow |
| } |
| |
| ; x < -k ? -k : (x > k ? k : x) |
| ; 8-bit base test |
| define i8 @sat_base_8bit(i8 %x) #0 { |
| ; CHECK-LABEL: sat_base_8bit: |
| ; V6T2: ssat r0, #6, r0 |
| ; V4T-NOT: ssat |
| entry: |
| %cmpLow = icmp slt i8 %x, -32 |
| %cmpUp = icmp sgt i8 %x, 31 |
| %saturateUp = select i1 %cmpUp, i8 31, i8 %x |
| %saturateLow = select i1 %cmpLow, i8 -32, i8 %saturateUp |
| ret i8 %saturateLow |
| } |
| |
| ; |
| ; Tests where the conditionals that check for upper and lower bounds, |
| ; or the < and > operators, are arranged in different ways. Only some |
| ; of the possible combinations that lead to SSAT are tested. |
| ; |
| |
| ; x < -k ? -k : (x < k ? x : k) |
| define i32 @sat_lower_upper_1(i32 %x) #0 { |
| ; CHECK-LABEL: sat_lower_upper_1: |
| ; V6T2: ssat r0, #24, r0 |
| ; V4T-NOT: ssat |
| entry: |
| %cmpLow = icmp slt i32 %x, -8388608 |
| %cmpUp = icmp slt i32 %x, 8388607 |
| %saturateUp = select i1 %cmpUp, i32 %x, i32 8388607 |
| %saturateLow = select i1 %cmpLow, i32 -8388608, i32 %saturateUp |
| ret i32 %saturateLow |
| } |
| |
| ; x > -k ? (x > k ? k : x) : -k |
| define i32 @sat_lower_upper_2(i32 %x) #0 { |
| ; CHECK-LABEL: sat_lower_upper_2: |
| ; V6T2: ssat r0, #24, r0 |
| ; V4T-NOT: ssat |
| entry: |
| %cmpLow = icmp sgt i32 %x, -8388608 |
| %cmpUp = icmp sgt i32 %x, 8388607 |
| %saturateUp = select i1 %cmpUp, i32 8388607, i32 %x |
| %saturateLow = select i1 %cmpLow, i32 %saturateUp, i32 -8388608 |
| ret i32 %saturateLow |
| } |
| |
| ; x < k ? (x < -k ? -k : x) : k |
| define i32 @sat_upper_lower_1(i32 %x) #0 { |
| ; CHECK-LABEL: sat_upper_lower_1: |
| ; V6T2: ssat r0, #24, r0 |
| ; V4T-NOT: ssat |
| entry: |
| %cmpUp = icmp slt i32 %x, 8388607 |
| %cmpLow = icmp slt i32 %x, -8388608 |
| %saturateLow = select i1 %cmpLow, i32 -8388608, i32 %x |
| %saturateUp = select i1 %cmpUp, i32 %saturateLow, i32 8388607 |
| ret i32 %saturateUp |
| } |
| |
| ; x > k ? k : (x < -k ? -k : x) |
| define i32 @sat_upper_lower_2(i32 %x) #0 { |
| ; CHECK-LABEL: sat_upper_lower_2: |
| ; V6T2: ssat r0, #24, r0 |
| ; V4T-NOT: ssat |
| entry: |
| %cmpUp = icmp sgt i32 %x, 8388607 |
| %cmpLow = icmp slt i32 %x, -8388608 |
| %saturateLow = select i1 %cmpLow, i32 -8388608, i32 %x |
| %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow |
| ret i32 %saturateUp |
| } |
| |
| ; k < x ? k : (x > -k ? x : -k) |
| define i32 @sat_upper_lower_3(i32 %x) #0 { |
| ; CHECK-LABEL: sat_upper_lower_3: |
| ; V6T2: ssat r0, #24, r0 |
| ; V4T-NOT: ssat |
| entry: |
| %cmpUp = icmp slt i32 8388607, %x |
| %cmpLow = icmp sgt i32 %x, -8388608 |
| %saturateLow = select i1 %cmpLow, i32 %x, i32 -8388608 |
| %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow |
| ret i32 %saturateUp |
| } |
| |
| ; |
| ; Miscellanea |
| ; |
| |
| ; Check that >= and <= work the same as > and < |
| ; k <= x ? k : (x >= -k ? x : -k) |
| define i32 @sat_le_ge(i32 %x) #0 { |
| ; CHECK-LABEL: sat_le_ge: |
| ; V6T2: ssat r0, #24, r0 |
| ; V4T-NOT: ssat |
| entry: |
| %cmpUp = icmp sle i32 8388607, %x |
| %cmpLow = icmp sge i32 %x, -8388608 |
| %saturateLow = select i1 %cmpLow, i32 %x, i32 -8388608 |
| %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow |
| ret i32 %saturateUp |
| } |
| |
| ; |
| ; The following tests check for patterns that should not transform |
| ; into SSAT but are similar enough that could confuse the selector. |
| ; |
| |
| ; x > k ? k : (x > -k ? -k : x) |
| ; First condition upper-saturates, second doesn't lower-saturate. |
| define i32 @no_sat_missing_lower(i32 %x) #0 { |
| ; CHECK-LABEL: no_sat_missing_lower |
| ; CHECK-NOT: ssat |
| entry: |
| %cmpUp = icmp sgt i32 %x, 8388607 |
| %cmpLow = icmp sgt i32 %x, -8388608 |
| %saturateLow = select i1 %cmpLow, i32 -8388608, i32 %x |
| %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow |
| ret i32 %saturateUp |
| } |
| |
| ; x < k ? k : (x < -k ? -k : x) |
| ; Second condition lower-saturates, first doesn't upper-saturate. |
| define i32 @no_sat_missing_upper(i32 %x) #0 { |
| ; CHECK-LABEL: no_sat_missing_upper: |
| ; CHECK-NOT: ssat |
| entry: |
| %cmpUp = icmp slt i32 %x, 8388607 |
| %cmpLow = icmp slt i32 %x, -8388608 |
| %saturateLow = select i1 %cmpLow, i32 -8388608, i32 %x |
| %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow |
| ret i32 %saturateUp |
| } |
| |
| ; Lower constant is different in the select and in the compare |
| define i32 @no_sat_incorrect_constant(i32 %x) #0 { |
| ; CHECK-LABEL: no_sat_incorrect_constant: |
| ; CHECK-NOT: ssat |
| entry: |
| %cmpUp = icmp sgt i32 %x, 8388607 |
| %cmpLow = icmp slt i32 %x, -8388608 |
| %saturateLow = select i1 %cmpLow, i32 -8388607, i32 %x |
| %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow |
| ret i32 %saturateUp |
| } |
| |
| ; The interval is not [k, ~k] |
| define i32 @no_sat_incorrect_interval(i32 %x) #0 { |
| ; CHECK-LABEL: no_sat_incorrect_interval: |
| ; CHECK-NOT: ssat |
| entry: |
| %cmpUp = icmp sgt i32 %x, 8388607 |
| %cmpLow = icmp slt i32 %x, -19088744 |
| %saturateLow = select i1 %cmpLow, i32 -19088744, i32 %x |
| %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow |
| ret i32 %saturateUp |
| } |
| |
| ; The returned value (y) is not the same as the tested value (x). |
| define i32 @no_sat_incorrect_return(i32 %x, i32 %y) #0 { |
| ; CHECK-LABEL: no_sat_incorrect_return: |
| ; CHECK-NOT: ssat |
| entry: |
| %cmpUp = icmp sgt i32 %x, 8388607 |
| %cmpLow = icmp slt i32 %x, -8388608 |
| %saturateLow = select i1 %cmpLow, i32 -8388608, i32 %y |
| %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow |
| ret i32 %saturateUp |
| } |
| |
| ; One of the values in a compare (y) is not the same as the rest |
| ; of the compare and select values (x). |
| define i32 @no_sat_incorrect_compare(i32 %x, i32 %y) #0 { |
| ; CHECK-LABEL: no_sat_incorrect_compare: |
| ; CHECK-NOT: ssat |
| entry: |
| %cmpUp = icmp sgt i32 %x, 8388607 |
| %cmpLow = icmp slt i32 %y, -8388608 |
| %saturateLow = select i1 %cmpLow, i32 -8388608, i32 %x |
| %saturateUp = select i1 %cmpUp, i32 8388607, i32 %saturateLow |
| ret i32 %saturateUp |
| } |
